100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS Page 258 InterviewSolution

12851.	My cat licks _____ tail every evening. But my dogs never lick _____ tails. A) its / their B) its / its C) their / its D) their / their
Answer» A) its / their

Discussion

12852.	Movement of substances in xylem is unidirectional while in phloem it is bidirectional. Why?
Answer» Xylem conducts ”Water and minerals in upward direction only but phloem conducts food in downward direction and in spring season stored food is again transported to upward for bud growth. Hence movement of substances in xylem is unidirectional while in phloem it is bidirectional.

Discussion

12853.	Both the xylem and phloem are tubular structures. One is unidirectional and the other is bi-directional. Comment on it.
Answer» Phloem is bidirectional in order to transport prepared food from leaves to different parts of the plant and translocates stored food from downward to upward for the growth of buds.

Discussion

12854.	Phloem transport is bidirectional while xylem transport is unidirectional. Give a reason?
Answer» Phloem transport is bidirectional because prepared food materials translocated to storage regions. These storage food materials are again transported to growing regions for the growth of buds. So, through phloem downward and upward transport takes place. Xylem transport is unidirectional because water and minerals are absorbed and conducted upwards.

Discussion

12855.	Explain why xylem transport is unidirectional and phloem transport bi-directional.
Answer» During the growth of a plant, its leaves act as the source of food as they carry out photosynthesis. The phloem conducts the food from the source to the sink (the part of the plant requiring or storing food). During spring, this process is reversed as the food stored in the sink is mobilised toward the growing buds of the plant, through the phloem. Thus, the movement of food in the phloem is bidirectional (i.e., upward and downward).The transport of water in the xylem takes place only from the roots to the leaves.Therefore, the movement of water and nutrients in the xylem is unidirectional.

Discussion

12856.	A fresh mango pieces is placed in water containing high concentration of sodium chloride. Exosmosis, Plasmolysis, Deplasmolysis, Imbibition1. Select and write down the appropriate terms given above to represent the sequence of events leading to shrinking.2. What is plasmolysis?
Answer» 1. Exosmosis – Plasmolysis 2. The withdrawal of the protoplast from the cell wall due to exosmosis.

12856.

A fresh mango pieces is placed in water containing high concentration of sodium chloride. Exosmosis, Plasmolysis, Deplasmolysis, Imbibition1. Select and write down the appropriate terms given above to represent the sequence of events leading to shrinking.2. What is plasmolysis?

Answer»

1. Exosmosis – Plasmolysis

2. The withdrawal of the protoplast from the cell wall due to exosmosis.

Discussion

12857.	When a freshly collected Spirogyra lament is kept in 10% potassium nitrate solution, it is observed that the protoplasm shrinks in size: 1. What is this phenomenon called?2. What will happen if the lament is replaced in distilled water?
Answer» 1. This phenomenon is called plasmolysis. (The shrinkage of protoplast from the cell wall under the influence of a strong solution/ hypertonic solution is called plasmolysis. 2. If laments are replaced in water the protoplast starts swelling. It comes in contact with cell wall and cell regains its original size. The swelling up of plasmolyzed protoplast under the influence of a weak solution or water is called deplasmolysis.

12857.

When a freshly collected Spirogyra lament is kept in 10% potassium nitrate solution, it is observed that the protoplasm shrinks in size: 1. What is this phenomenon called?2. What will happen if the lament is replaced in distilled water?

Answer»

1. This phenomenon is called plasmolysis. (The shrinkage of protoplast from the cell wall under the influence of a strong solution/ hypertonic solution is called plasmolysis.

2. If laments are replaced in water the protoplast starts swelling. It comes in contact with cell wall and cell regains its original size. The swelling up of plasmolyzed protoplast under the influence of a weak solution or water is called deplasmolysis.

Discussion

12858.	Ψw = Ψs + Ψp 1. Expand the equation. 2. Why solute potential is always negative?
Answer» 1. Ψ_w – Water potential Ψ_s – Solute potential, Ψ_p – pressure potential 2. Since adding solute reduces water potential, it is always negative.

12858.

Ψw = Ψs + Ψp 1. Expand the equation. 2. Why solute potential is always negative?

Answer»

1.

Ψ_w – Water potential

Ψ_s – Solute potential,

Ψ_p – pressure potential

2. Since adding solute reduces water potential, it is always negative.

Discussion

12859.	Water is absorbed by the root hairs, It can move deeper into root layers by two distinct pathways. 1. Write the name of the pathways. 2. Which substance controls water transport in the endodermal region?
Answer» 1. Apoplast pathway & Symplast pathway 2. Suberin

12859.

Water is absorbed by the root hairs, It can move deeper into root layers by two distinct pathways. 1. Write the name of the pathways. 2. Which substance controls water transport in the endodermal region?

Answer»

1. Apoplast pathway & Symplast pathway

2. Suberin

Discussion

12860.	Apoplast and symplast pathways are the two distinct pathways of water to move deeper into the root layers. Which is the only pathway through which water can enter the vascular cylinder and why?
Answer» Symplast – Because endodermal wall is suberised.

Discussion

12861.	Some vascular bundles are described as open because theseA. are surrounded by pericycle but no endodermisB. are capable of producing secondary xylem and phloemC. possess conjunctive tissue between xylem and phloemD. are not surrounded by pericycle
Answer» Correct Answer - B

Discussion

12862.	Which is/are correct among the following? Given the half cell EMFs `E_(Cu^(2+)//Cu)^(@)=0.337V, E_(Cu^(+)\|Cu)^(@)=0.521V`A. `Cu^(+1)` disproportionates.B. Cu and `Cu^(2+)` comproportionates (reverse of disproportionation into `Cu^(+)`).C. `E_(Cu\|Cu^(+2))^(0)+E_(Cu^(+1)\|Cu)^(0)` is positiveD. All of these
Answer» Correct Answer - A,B,C `({:(Cu^(+)toCu^(2+)+Cu),(E_("cell")^(0)=E_(Cu^+\|Cu^(+2))^(0)+E_(Cu^+\|Cu)),(1e^(-)+Cu^(+)toCu),(Cu to Cu^(2+)+2e^(-)):})/({:Cu^+ toCu^(+2)+1e^(-):})` `E_(Cu^(+)\|Cu^(2+)=1xx0.521-2xx0.337=-0.153` `E_(cell)^0=-0.153+0.521=0.368` reaction is spontaneous

Discussion

12863.	Indicate the correct statements :A. Conductivity cells have cell constant values Independent of the solution filled into the cellB. DC (direct current) is not used for measuring the resistance of a solution.C. Kohlrausch law is valid both for strong and weak electrolytes.D. The k decreases but `lambda_M` and `lambda_E` increase on dilution.
Answer» Correct Answer - A,B,C,D cell constant =`l/A` `K=Gsigma " " lambda_(M)=(1000K)/M, lambda_(N)=(1000K)/N` On dilution `Gdarr K darr Mdarr Ndarr lambda_Muarr, lambda_N uarr`

Discussion

12864.	Arrange the steps of catalytic action of an enzyme in order and select the correct option I. The enzyme releases the products of the reaction and the enzyme is free to bind to another substrate II. The active site of enzyme is in close proximity of the substrate and breaks the chemical bonds of the substrate III. The binding of substrate induces the enzyme to alter its shape fitting more tightly around substrate. VI. The substrate binds to the active site of the enzymeA. IV,II,II,IB. III,II,I,IVC. IV,II,I,IID. II,I,IV,III
Answer» Correct Answer - A

Discussion

12865.	A current of `2.68A` is passed for one hour through an aqeous solution of `CuSO_(4)` using copper electrodes. Select the correct statement (s) from the followingA. increase in mass of cathode=3.174 gB. decrease in mass of anode=3.174 gC. no change in masses of electrodesD. the ratio between the change of masses of cathode and anode is 1:2
Answer» Correct Answer - A,C `{:("At Cathode:"Cu^(2+) + 2e^(-) to Cu(S)),("At Anode:"Cu(s) to Cu^(2+)+2e^(-)):}` Increase in mass of cathode = decrease in mass in Anode =`(2.68xx3600)/96500xx63.5/2=3.174 g`

Discussion

12866.	Histamine is formed from histidine by the enzyme histidine decarboxylase in the presence of (A) NAD (B) FMN (C) HS-CoA (D) B6-PO4
Answer» Correct option (D) B₆-PO₄

12866.

Histamine is formed from histidine by the enzyme histidine decarboxylase in the presence of (A) NAD (B) FMN (C) HS-CoA (D) B6-PO4

Answer»

Correct option (D) B₆-PO₄

Discussion

12867.	The product of two consecutive odd numbers is 19043. Which is the smaller number?(a) 137 (b) 131(c) 133 (d) 129(e) None of these
Answer» (a) Out of the given alternatives, 137 × 139 = 19043 Required smaller number = 137

Discussion

12868.	The compound that does not undergo hydrolysis by `S_(N^(1))` mechanism is :A. `H_(2)C=CHCH_(2)Cl`B. `C_(6)H_(5)Cl`C. `C_(6)H_(5)CH_(2)Cl`D. `C_(6)H_(5)CH(C_(6)H_(5))Cl`
Answer» Correct Answer - B

Discussion

12869.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, how many moles of water are produced?(a) 1(b) 2(c) 3(d) 4
Answer» The correct choice is (a) 1 Explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. 5nH2Op = nH2Sp, => 5 nH2Op = 30 – 2(12.5) = 5, => nH2Op = 1.

Discussion

12870.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what fraction of limiting reagent is converted into product?(a) 0.21(b) 0.46(c) 0.73(d) 0.83
Answer» The correct answer is (d) 0.83 For explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles, => limiting reagent is H2S, => fraction of H2S converted into product = 2E/F = 2(1.25)/3 = 0.83.

Discussion

12871.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what is the rate of streams?(a) 10 mole(b) 20 moles(c) 30 moles(d) 40 moles
Answer» Correct option is (c) 30 moles The best explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles.

Discussion

12872.	A reactor is supplied with 2 streams both at same rates, one has pure Cl2, and another has pure C2H6, if the product has 20% C2H5Cl and 50% HCl and 30% C2H6, what is the ratio of rate of feed and rate of product?(a) 0.2(b) 0.5(c) 2(d) 5
Answer» The correct option is (b) 0.5 For explanation: The reaction is C2H6 + Cl2 -> C2H5Cl + HCl, Let the rate of feed and products be F and P respectively. Element balances, C: F(2) – 0.3P(2) = 0.2P(2), => F/P = 0.5.

Discussion

12873.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what is percentage of Sulfur in the product?(a) 23%(b) 47%(c) 61%(d) 84%
Answer» Correct choice is (c) 61% Easiest explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => Moles of SO2 = 0.75F – E = 10, moles of H2S = F – 2E = 5, moles of N2 = 7.5, moles of S = 37.5, moles of H2O = 1, => percentage of sulfur = 61%.

Discussion

12874.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CO are produced?(a) 1(b) 2(c) 3(d) 4
Answer» Right choice is (b) 2 Explanation: Extent of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of CO = (0.85)0.5 = 2.

Discussion

12875.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CH2O came out of the reactor?(a) 1(b) 2(c) 3(d) 4
Answer» Correct option is (b) 2 Easiest explanation: Extent of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of CH2O unreacted = 0.85 – (0.85)*0.5 = 2.

Discussion

12876.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CH3OH are there in the products?(a) 1(b) 2(c) 3(d) 4
Answer» Correct option is (a) 1 For explanation I would say: Extent of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of CH3OH = 5 – 5*0.8 = 1.

Discussion

12877.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of O2 are there in the products?(a) 1.75(b) 2(c) 3.25(d) 5.5
Answer» Correct choice is (a) 1.75 The best explanation: Extent of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of O2 = (2.5 – 2.50.8) + (2.5 – 2.50.5) = 1.75.

Discussion

12878.	`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `08(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None
Answer» Correct Answer - C

Discussion

12879.	`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `108(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None
Answer» Correct Answer - c

Discussion

12880.	Which of the following is a natural polymer ? (1) poly (Butadiene-acrylonitrile) (2) cis-1,4-polyisoprene (3) poly (Butadiene-styrene) (4) polybutadiene
Answer» (2) cis-1,4-polyisoprene

12880.

Which of the following is a natural polymer ? (1) poly (Butadiene-acrylonitrile) (2) cis-1,4-polyisoprene (3) poly (Butadiene-styrene) (4) polybutadiene

Answer»

(2) cis-1,4-polyisoprene

Discussion

12881.	The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol–1) is : (1) 4 (2) 1 (3) 2 (4) 3
Answer» (2) 1 Ca⁺² + 2e^– ® Ca_(s) v.f. = 2 As per faraday's 1^st law Charge passed in faraday = g.eq of product = ´20/40 x 2 = 1F w=ZQ. => Q=w/Z = 20/40/2 F = 1Fw=ZQ. => Q=w/Z = 20/40/2 F = 1FAs per faraday's 1st law Charge passed in faraday = g.eq of productw=ZQ. => Q=w/Z = 20/40/2 F = 1F As per faraday's 1st law Charge passed in faraday = g.eq of product

12881.

The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol–1) is : (1) 4 (2) 1 (3) 2 (4) 3

Answer»

(2) 1

Ca⁺² + 2e^– ® Ca_(s)

v.f. = 2

As per faraday's 1^st law Charge passed in faraday = g.eq of product

= ´20/40 x 2

= 1F

w=ZQ.   => Q=w/Z

                     = 20/40/2 F

                     = 1Fw=ZQ.   => Q=w/Z

                     = 20/40/2 F

                     = 1FAs per faraday's 1st law Charge passed in faraday = g.eq of productw=ZQ.   => Q=w/Z

                     = 20/40/2 F

                     = 1F

As per faraday's 1st law Charge passed in faraday = g.eq of product

Discussion

12882.	Which of the following is not correct about carbon monoxide? (1) It is produced due to incomplete combustion (2) It forms carboxyhaemoglobin (3) It reduce oxygen carrying ability of blood (4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.
Answer» (4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin. Not correct Carboxyhaemoglobin (haemoglobin bound to CO) is more stable than oxyhaemoglobin.

12882.

Which of the following is not correct about carbon monoxide? (1) It is produced due to incomplete combustion (2) It forms carboxyhaemoglobin (3) It reduce oxygen carrying ability of blood (4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

Answer»

(4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

Not correct

Carboxyhaemoglobin (haemoglobin bound to CO) is more stable than oxyhaemoglobin.

Discussion

12883.	The rate constant for a first order reaction is 4.606 × 10–3 s–1 . The time required to reduce 2.0 g of the reactant to 0.2 g is : (1) 1000 s (2) 100 s(3) 200 s (4) 500 s
Answer» (4) 500 s k = 4.606 × 10^–3 s^–1 kt = 2.303log₁₀ 2/0.2 4.606 x 10^-3x t = 2.303 x log10 t = 1000/2 = 500s

12883.

The rate constant for a first order reaction is 4.606 × 10–3 s–1 . The time required to reduce 2.0 g of the reactant to 0.2 g is : (1) 1000 s (2) 100 s(3) 200 s (4) 500 s

Answer»

(4) 500 s

k = 4.606 × 10^–3 s^–1

kt = 2.303log₁₀ 2/0.2

4.606 x 10^-3x t = 2.303 x log10

t = 1000/2

= 500s

Discussion

12884.	Which element on treatment with caustic soda solution produces `H_(2)` gas?
Answer» Correct Answer - `Sn,Al`

Discussion

12885.	The mixture which shows positive deviation from Raoult's law is :- (1) Chloroethane + Bromoethane (2) Ethanol + Acetone (3) Benzene + Toluene (4) Acetone + Chloroform
Answer» (2) Ethanol + Acetone Hydrogen bond of ethanol gets weakened by addition of acetone

12885.

The mixture which shows positive deviation from Raoult's law is :- (1) Chloroethane + Bromoethane (2) Ethanol + Acetone (3) Benzene + Toluene (4) Acetone + Chloroform

Answer»

(2) Ethanol + Acetone

Hydrogen bond of ethanol gets weakened by addition of acetone

Discussion

12886.	A white crystalline solid (A) on boiling with caustic soda solution gave a gas (B) which when passed through an alkaline solution of `K_(2) [HgI_(4)]` gave a brown precipitate. The substance (A) on heating gave a gasa (X) which rekindled a glowing splinter but does not give brown fumes with nitric oxide. The gas (X) is:A. `NH_(3)`B. `O_(2)`C. `O_(3)`D. `N_(2)O`
Answer» Correct Answer - D The white crystalline solid (A) is`NH_(4)NO_(3)` `underset((A))(NH_(4)NO_(3))rarrNaNO_(3)+underset((B))(NH_(3))+H_(2)O` `underset((B))(NH_(3))+3KOH+2K_(2)[HgI_(4)]rarr H_(2)N-underset(("Brown ppt"))(Hg-O)-Hg-I+7KI+2H_(2)O` `NH_(4)NO_(3)overset(Delta)rarrunderset(("x"))(N_(2)O)+2H_(2)O` `C+2N_(2)O rarr CO_(2)+2N_(2)`

Discussion

12887.	The correct statement(s) about , `HCIO_(4)` and `HCIO`, isA. `HClO_(4)` is more acidic than HClO because of resonance stabilization of its anionB. The central atom in both `HClO_(4)` and `HClO` is `sp^(3)` hybridizedC. `HClO_(4)` is formed in the reaction between `Cl_(2)` and `H_(2)O`D. The conjugate base of `HClO_(4)` is weaker base than `H_(2)O`
Answer» Correct Answer - A::B::D

Discussion

12888.	Which equation gives the relationship between equivalent or molar conductance and concentration of a strong electrolyte ?
Answer» Debye`-` Huckel `-` Onsager equation `:` `wedge_(m)=wedge^(@)``_(m)-Asqrt(c)`

Discussion

12889.	Argentite is a mineral ofA. CopperB. SilverC. PlatinumD. Gold
Answer» Correct Answer - B Argentite or silver glance `(Ag_(2)S)`

Discussion

12890.	Calculate the volume of the gaseous products at NTP obtained by the electrolysis of acidulated water using 10A current for 20 minutes
Answer» The quantity of electricity passed = current strength (I)xTime (t)= 10x20x60C=12000/96500 = 12/965 Faraday I Faraday electricity generates 1 g equivalent substance in the electrode. So 1 Faraday electricity will produce 1 g equivalent Hydrogen or 1g or 1/2 =0.5mole of hydrogen.at cathode. and 1 Faraday electricity will simultaneously produce 1g equivalent or 8g of Oxygen or 1/4=0.25 mole Oxygen at anode So total 0.75 mole of gas will be produced on electrolysis. The volume of this 0.75 mole gas at NTP will be = 0.75x22.4L=16.8 L for passage of 1 Faraday of electricity. Hence the passage of 12/965 Faraday electricity will produce 12/965 x16.8 L=02089L gas

Discussion

12891.	A sample of Ammonium phosphate `(NH_(4))_(3)PO_(4)` contains 3.18 moles of oxygen atoms. The number of moles of oxygen atom in the sample isA. 0.265B. 0.795C. 1.06D. 3.18
Answer» Correct Answer - 3 `because` 12 moles of hydrogen in the sample `therefore` 1 moles of hydrogen=`4/12` mole of oxygen `therefore` 3.18 mole of hydrogen=`4/12xx3.18` =1.06 moles of oxygen

Discussion

12892.	The volume of 0.01 M KMnO4 solution which can oxidize 20 ml of 0.05 M Mohr salt solution in acidic medium is(a) 10 ml(b) 20 ml(c) 30 ml(d) 40 ml
Answer» Correct option is (b) 20 m MIV₁Z₁ = M₂V₂Z₂ 0.01 x V₁ x 5 = 0.05 x 20 x 1 V₁ = 20 ml

12892.

The volume of 0.01 M KMnO4 solution which can oxidize 20 ml of 0.05 M Mohr salt solution in acidic medium is(a) 10 ml(b) 20 ml(c) 30 ml(d) 40 ml

Answer»

Correct option is (b) 20 m

MIV₁Z₁ = M₂V₂Z₂

0.01 x V₁ x 5 = 0.05 x 20 x 1

V₁ = 20 ml

Discussion

12893.	The rate cosntant of first order reaction is `6.8 xx 10^(-4) s^(-1)` If the initial concentration of the reactant is 0.04 M , What is its molarity after 20 minutes ? How long will it take for 25% of the reactant to react ?
Answer» Correct Answer - (i) Molarity of reactant after 20 min =0.0177 M (ii) Time for 25% of the reaction = 7.05 min Given : Rate constant `=k = 6.8 xx 10^(-4) s^(-1)` `[A]_(0) =0.04 M` (i) After t= 20 min = 20 x 60 s = 1200 s `[A]_(t) = ?` `k= (2.303)/(t) log_(10) .([A]_(0))/([A]_(t))` `:. log_(10).[[A]_(0)]/[[A]_(t)] = (kxxt)/(2.303) - (6.8 xx 10^(-4) xx 1200)/(2.303 ) = 0.3543` `:. [[A]_(0)]/[[A]_(t)]=AL 0.3543 =2.26` `:. [A]_(t) =[[A]_(0))/(2.26) =(0.04)/(2.26) =0.0177 M` (ii) For 25% reactant to react t= ? Reactant reacted =25% of 0.04 M `=(25)/(100) xx 0.04` `=0.01 M` `:.` Reactant left `=[A]_(t) = 0.04 - 0.01 =0.03 M` `t= (2.303)/(k) log_(10) .([[A]_(0)])/([[A]_(t)])` `=(2.303)/(6.8 xx 10^(-4)) log_(10) .(0.04)/(0.03)` `=(2.303)/(6.8xx 10^(-4))` `=423 s` `=(423)/(60) min = 7.05 min`

Discussion

12894.	The decomposition of `N_(2) O_(5)` is represented by the equation `2N_(2)O_(5(g)) to 4NO_(2(g)) + O_(2(g))` (a ) How is the rate of formation of `NO_(2)` related to the rate of formation of `O_(2)`? (b ) How is the rate of formation of `O_(2)` related to the rate of consumption of `N_(2)O_(s)?`
Answer» Given : `2N_(2)O_(5(g)) to 4NO_(2(g)) + O_(2(g))` (a) Rate of formation of `O_(2)` at time `t= (d[O_(2)])/(dt)` They are related to each other through rate of reaction `:. ` Rate of reaction `=(1)/(4) (d[NO_(2)])/(dt)= (d[O_(2)])/(dt)` ( b) Rate of consumption of `N_(2) O_(5)` at time `t= - (d[N_(2)O_(5)])/(dt)` Rate of reaction `=- (1)/(2) (d[N_(2)O_(5)])/(dt) =(d[O_(2)])/(dt)` In general Rate of reaction `= -(1)/(2) (d[N_(2)O_(5)])/(dt)= (1)/(4) (d[NO_(2)])/(dt)= (d[O_(2)])/(dt)`

Discussion

12895.	Ammonia and oxygen react at high temperature as : `4NH_(a(g)) + 5O_(2(g))to 4NO_((g)) +6H_(2)O_((g))` In an experiment rate of formation of `NO_((g))` is `3.6 xx 10^(-3) mol L^(-1) s^(-1)` Calculate (a) Rate of disappearance of ammonia ( b) Rate of formation of water .
Answer» Correct Answer - (a) Rate of disappearance of `NH_(2) = 3.6 xx 10^(-3) mol L^(-1) s^(-1)` ( b) Rate of formation of `H_(2)O =5.4 xx 10^(-3) mol L^(-1) s^(-1)` Given : `4NH_(5(g)) +5O_(2(g)) to 4NO_((g)) + 6H_(2)O_((g))` `(d[NO])/(dt) = 3.6 xx 10^(-3) mol L ^(-1) s^(-1)` (a) `-(1)/(4) (d[NH_(3)])/(dt) =(1)/(4) (d[NO])/(dt)` `:.` Rate of disappearance of `NH_(3)` `=(-d[NH_(3)])/(dt) = (d[NO])/(dt)` `=3.6 xx 10^(-3) mol L^(-1) s^(-1)` `:.` Rate of formation of `H_(2)O` `=(d[H_(2)O])/(dt)=(6)/(4) (d[NO])/(dt)` `=(6)/(4) xx 3.6 xx10^(-3)` `=5.4 xx 10^(-3) mol L^(-1) s^(-1)`

Discussion

12896.	If `C(s)+O_(2)(g)to CO_(2)(g),DeltaH=rand CO(g)+1/2O_(2)to CO_(2)(g),DeltaH=s` then, the heat of formation of CO isA. `-Y-X`B. `Y-X`C. `X+Y`D. X -Y`
Answer» Correct Answer - B `C(s) + O_(2) (g) to CO_(2) (g), Delta H_(1) = - x` …(i) `CO (g) + (1)/(2) O_(2) (g) to CO_(2) (g), Delta H_(2) = - y` ….(ii) For the formation of CO subtract Eqs. (ii) from (i) i.e. `C(s) + O_(2) (g) to CO_(2) (g)` `underline(underset((-))(CO(g) + (1)/(2) underset((-))(O_(2) (g)) to underset((-))(CO_(2)(g)))` `underline(C(s) + (1)/(2) O_(2) (g) to CO (g))` `:. Delta_(r ) H` for formation of `CO = Delta H_(1) - Delta H_(2)` = - x + y or y - x

Discussion

12897.	(i) The survey statistics mention the average stipend, indicating that A. 50% interns were offered ₹85,000. B. ₹7,000 was the lowest and ₹85,000 was the highest. C. most interns were offered around ₹7,000. D. No intern was offered more than ₹7,000.(ii) The phrase ‘healthy traffic’ refers to the A. updates from portals about health and road safety. B. statistics about adherence to traffic rules by the portals. C. sizeable number of visitors to the portal per month. D. monthly data about the health of internship applicants.(iii) Read the two statements given below and select the option that suitably explains them. (1) Established companies are reluctant to take too many interns on board. (2) Probability of interns leaving the company for a variety of reasons, is high. A. (1) is the problem and (2) is the solution for (1). B. (1) is false but (2) correctly explains (1). C. (1) summarises (2). D. (1) is true and (2) is the reason for (1).
Answer» (i) C. most interns were offered around ₹7,000. (ii) C. sizeable number of visitors to the portal per month. (1) belief (1) part humourous, part earnestness (iii) D. (1) is true and (2) is the reason for (1).

12897.

(i) The survey statistics mention the average stipend, indicating that A. 50% interns were offered ₹85,000. B. ₹7,000 was the lowest and ₹85,000 was the highest. C. most interns were offered around ₹7,000. D. No intern was offered more than ₹7,000.(ii) The phrase ‘healthy traffic’ refers to the A. updates from portals about health and road safety. B. statistics about adherence to traffic rules by the portals. C. sizeable number of visitors to the portal per month. D. monthly data about the health of internship applicants.(iii) Read the two statements given below and select the option that suitably explains them. (1) Established companies are reluctant to take too many interns on board. (2) Probability of interns leaving the company for a variety of reasons, is high. A. (1) is the problem and (2) is the solution for (1). B. (1) is false but (2) correctly explains (1). C. (1) summarises (2). D. (1) is true and (2) is the reason for (1).

Answer»

(i) C. most interns were offered around ₹7,000.

(ii) C. sizeable number of visitors to the portal per month. (1) belief (1) part humourous, part earnestness

(iii) D. (1) is true and (2) is the reason for (1).

Discussion

12898.	chemical formula
Answer» The common indicator cannot give us the strength of acid and base. To measure the strength of acid and bases we need a universal indicator. Universal indicator is a mixture of different indicators which give different colour at different pH value of entire scale.

Discussion

12899.	Why does boron trifluoride behave as a Lewis acid?
Answer» The B atom in BF₃ has only 6 electrons in the valence shell and thus needs two more electrons to complete its octet. Therefore, it easily accepts a pair of electrons from nucleophiles such as F^- , NH₃ , (C₂H₅)₂O, RCH₂OH etc. and thus behaves as a Lewis acid.

Discussion

12900.	1. Boron resembles silicon in many of its properties. What is this resemblance generally known as? 2. What is dry ice? What is it used for? 3. What are silicones? How do they differ from silicates?
Answer» 1. Diagonal relationship 2. Carbon dioxide can be obtained as a solid in the form of dry ice, by allowing the liquied CO₂ to expand rapidly. Dry ice is used as a refrigerant for ice-cream and frozen food. 3. Silicones are a group of organosilicon polymers containing R₂SiO repeating units. Silicates are minerals with SiO^4-₄ as the basic structural unit. In silicates either the discrete unit is present or a number of such units are joined together via corners by sharing 1, 2, 3 or 4 oxygen atoms per silicate units.

12900.

1. Boron resembles silicon in many of its properties. What is this resemblance generally known as? 2. What is dry ice? What is it used for? 3. What are silicones? How do they differ from silicates?

Answer»

1. Diagonal relationship

2. Carbon dioxide can be obtained as a solid in the form of dry ice, by allowing the liquied CO₂ to expand rapidly. Dry ice is used as a refrigerant for ice-cream and frozen food.

3. Silicones are a group of organosilicon polymers containing R₂SiO repeating units. Silicates are minerals with SiO^4-₄ as the basic structural unit. In silicates either the discrete unit is present or a number of such units are joined together via corners by sharing 1, 2, 3 or 4 oxygen atoms per silicate units.

Discussion

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A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, how many moles of water are produced?(a) 1(b) 2(c) 3(d) 4

A reactor is supplied with 2 streams both at same rates, one has pure Cl2, and another has pure C2H6, if the product has 20% C2H5Cl and 50% HCl and 30% C2H6, what is the ratio of rate of feed and rate of product?(a) 0.2(b) 0.5(c) 2(d) 5

`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `08(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None

`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `108(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None

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Which of the following is not correct about carbon monoxide? (1) It is produced due to incomplete combustion (2) It forms carboxyhaemoglobin (3) It reduce oxygen carrying ability of blood (4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

The rate constant for a first order reaction is 4.606 × 10–3 s–1 . The time required to reduce 2.0 g of the reactant to 0.2 g is : (1) 1000 s (2) 100 s(3) 200 s (4) 500 s

Which element on treatment with caustic soda solution produces `H_(2)` gas?

The mixture which shows positive deviation from Raoult's law is :- (1) Chloroethane + Bromoethane (2) Ethanol + Acetone (3) Benzene + Toluene (4) Acetone + Chloroform

Which equation gives the relationship between equivalent or molar conductance and concentration of a strong electrolyte ?

Argentite is a mineral ofA. CopperB. SilverC. PlatinumD. Gold

Calculate the volume of the gaseous products at NTP obtained by the electrolysis of acidulated water using 10A current for 20 minutes

A sample of Ammonium phosphate `(NH_(4))_(3)PO_(4)` contains 3.18 moles of oxygen atoms. The number of moles of oxygen atom in the sample isA. 0.265B. 0.795C. 1.06D. 3.18

The volume of 0.01 M KMnO4 solution which can oxidize 20 ml of 0.05 M Mohr salt solution in acidic medium is(a) 10 ml(b) 20 ml(c) 30 ml(d) 40 ml

The rate cosntant of first order reaction is `6.8 xx 10^(-4) s^(-1)` If the initial concentration of the reactant is 0.04 M , What is its molarity after 20 minutes ? How long will it take for 25% of the reactant to react ?

The decomposition of `N_(2) O_(5)` is represented by the equation `2N_(2)O_(5(g)) to 4NO_(2(g)) + O_(2(g))` (a ) How is the rate of formation of `NO_(2)` related to the rate of formation of `O_(2)`? (b ) How is the rate of formation of `O_(2)` related to the rate of consumption of `N_(2)O_(s)?`

Ammonia and oxygen react at high temperature as : `4NH_(a(g)) + 5O_(2(g))to 4NO_((g)) +6H_(2)O_((g))` In an experiment rate of formation of `NO_((g))` is `3.6 xx 10^(-3) mol L^(-1) s^(-1)` Calculate (a) Rate of disappearance of ammonia ( b) Rate of formation of water .

If `C(s)+O_(2)(g)to CO_(2)(g),DeltaH=rand CO(g)+1/2O_(2)to CO_(2)(g),DeltaH=s` then, the heat of formation of CO isA. `-Y-X`B. `Y-X`C. `X+Y`D. X -Y`

chemical formula

Why does boron trifluoride behave as a Lewis acid?

1. Boron resembles silicon in many of its properties. What is this resemblance generally known as? 2. What is dry ice? What is it used for? 3. What are silicones? How do they differ from silicates?

Explore topic-wise InterviewSolutions in .

My cat licks _____ tail every evening. But my dogs never lick _____ tails. A) its / their B) its / its C) their / its D) their / their

Movement of substances in xylem is unidirectional while in phloem it is bidirectional. Why?

Both the xylem and phloem are tubular structures. One is unidirectional and the other is bi-directional. Comment on it.

Phloem transport is bidirectional while xylem transport is unidirectional. Give a reason?

Explain why xylem transport is unidirectional and phloem transport bi-directional.

A fresh mango pieces is placed in water containing high concentration of sodium chloride. Exosmosis, Plasmolysis, Deplasmolysis, Imbibition1. Select and write down the appropriate terms given above to represent the sequence of events leading to shrinking.2. What is plasmolysis?

When a freshly collected Spirogyra lament is kept in 10% potassium nitrate solution, it is observed that the protoplasm shrinks in size: 1. What is this phenomenon called?2. What will happen if the lament is replaced in distilled water?

Ψw = Ψs + Ψp 1. Expand the equation. 2. Why solute potential is always negative?

Water is absorbed by the root hairs, It can move deeper into root layers by two distinct pathways. 1. Write the name of the pathways. 2. Which substance controls water transport in the endodermal region?

Apoplast and symplast pathways are the two distinct pathways of water to move deeper into the root layers. Which is the only pathway through which water can enter the vascular cylinder and why?

Some vascular bundles are described as open because theseA. are surrounded by pericycle but no endodermisB. are capable of producing secondary xylem and phloemC. possess conjunctive tissue between xylem and phloemD. are not surrounded by pericycle

Histamine is formed from histidine by the enzyme histidine decarboxylase in the presence of (A) NAD (B) FMN (C) HS-CoA (D) B6-PO4

The product of two consecutive odd numbers is 19043. Which is the smaller number?(a) 137 (b) 131(c) 133 (d) 129(e) None of these

The compound that does not undergo hydrolysis by `S_(N^(1))` mechanism is :A. `H_(2)C=CHCH_(2)Cl`B. `C_(6)H_(5)Cl`C. `C_(6)H_(5)CH_(2)Cl`D. `C_(6)H_(5)CH(C_(6)H_(5))Cl`

A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, how many moles of water are produced?(a) 1(b) 2(c) 3(d) 4

A reactor is supplied with 2 streams both at same rates, one has pure Cl2, and another has pure C2H6, if the product has 20% C2H5Cl and 50% HCl and 30% C2H6, what is the ratio of rate of feed and rate of product?(a) 0.2(b) 0.5(c) 2(d) 5

`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `08(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None

`A_(3)B_(2)` is a sparingly soluble salt with molar mass `M(gmol_(-))` and solubility `x` gm `litre_(-1)`, the ratio of the molar concentration of `B^(3-)` to the solubilty product of the salt is `:-`A. `108(x^(5))/(M^(5))`B. `(1)/(108)(M^(4))/(x^(4))`C. `(1)/(54)(M^(4))/(x^(4))`D. None

Which of the following is a natural polymer ? (1) poly (Butadiene-acrylonitrile) (2) cis-1,4-polyisoprene (3) poly (Butadiene-styrene) (4) polybutadiene

The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol–1) is : (1) 4 (2) 1 (3) 2 (4) 3

Which of the following is not correct about carbon monoxide? (1) It is produced due to incomplete combustion (2) It forms carboxyhaemoglobin (3) It reduce oxygen carrying ability of blood (4) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

The rate constant for a first order reaction is 4.606 × 10–3 s–1 . The time required to reduce 2.0 g of the reactant to 0.2 g is : (1) 1000 s (2) 100 s(3) 200 s (4) 500 s

Which element on treatment with caustic soda solution produces `H_(2)` gas?

The mixture which shows positive deviation from Raoult's law is :- (1) Chloroethane + Bromoethane (2) Ethanol + Acetone (3) Benzene + Toluene (4) Acetone + Chloroform

Which equation gives the relationship between equivalent or molar conductance and concentration of a strong electrolyte ?

Argentite is a mineral ofA. CopperB. SilverC. PlatinumD. Gold

Calculate the volume of the gaseous products at NTP obtained by the electrolysis of acidulated water using 10A current for 20 minutes

A sample of Ammonium phosphate `(NH_(4))_(3)PO_(4)` contains 3.18 moles of oxygen atoms. The number of moles of oxygen atom in the sample isA. 0.265B. 0.795C. 1.06D. 3.18

The volume of 0.01 M KMnO4 solution which can oxidize 20 ml of 0.05 M Mohr salt solution in acidic medium is(a) 10 ml(b) 20 ml(c) 30 ml(d) 40 ml

The rate cosntant of first order reaction is `6.8 xx 10^(-4) s^(-1)` If the initial concentration of the reactant is 0.04 M , What is its molarity after 20 minutes ? How long will it take for 25% of the reactant to react ?

The decomposition of `N_(2) O_(5)` is represented by the equation `2N_(2)O_(5(g)) to 4NO_(2(g)) + O_(2(g))` (a ) How is the rate of formation of `NO_(2)` related to the rate of formation of `O_(2)`? (b ) How is the rate of formation of `O_(2)` related to the rate of consumption of `N_(2)O_(s)?`

Ammonia and oxygen react at high temperature as : `4NH_(a(g)) + 5O_(2(g))to 4NO_((g)) +6H_(2)O_((g))` In an experiment rate of formation of `NO_((g))` is `3.6 xx 10^(-3) mol L^(-1) s^(-1)` Calculate (a) Rate of disappearance of ammonia ( b) Rate of formation of water .

If `C(s)+O_(2)(g)to CO_(2)(g),DeltaH=rand CO(g)+1/2O_(2)to CO_(2)(g),DeltaH=s` then, the heat of formation of CO isA. `-Y-X`B. `Y-X`C. `X+Y`D. X -Y`

chemical formula

Why does boron trifluoride behave as a Lewis acid?

1. Boron resembles silicon in many of its properties. What is this resemblance generally known as? 2. What is dry ice? What is it used for? 3. What are silicones? How do they differ from silicates?

My cat licks _ tail every evening. But my dogs never lick _ tails. A) its / their B) its / its C) their / its D) their / their