100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS Page 398 InterviewSolution

19851.	Figure shows `4` identical masses of mass `m`, arranged on a cube as shown. The potential energy of the system is A. it will collide with one of the massesB. It execute an oscillatory motion (not SHM)C. It executes SHMD. none of these
Answer» `PE=6xx(GM^(2))/(sqrt(2)a)` `=-3sqrt(2)(GM^(2))/(a)` `F=3xx(GM^(2))/(2a^(2))xx(sqrt(2))/(sqrt(3))=sqrt((3)/(2))(GM^(2))/(a^(2))`

Discussion

19852.	When we raise the temperature of a body, the molecules and atoms move with greater kinetic enery. Assume that "the temperature" is the manifestation of only the kinetic energy is atomic and subatomic levels and no mass change (excess//defect) occurs due to heating. Now a solid material is supplied with heat at a constant rate. The temperature of the material is changing with the heat input as shown in the graph. `BC` and `DE` are parallel to the Heat-input axis In `AB`, `CD` and `EF`, the energy of the system increases. Here "energy" refers to A. kinetic energyB. potential energyC. both kinetic and potential energyD. none of these
Answer» In `AB`, `CD` and `EF` Temperature increases `rArr K.E.` increases

Discussion

19853.	When we raise the temperature of a body, the molecules and atoms move with greater kinetic enery. Assume that "the temperature" is the manifestation of only the kinetic energy is atomic and subatomic levels and no mass change (excess//defect) occurs due to heating. Now a solid material is supplied with heat at a constant rate. The temperature of the material is changing with the heat input as shown in the graph. `BC` and `DE` are parallel to the Heat-input axis In which of the following phase the assumption made in the above comprehension is most precise ? A. solidB. liquidC. gasD. not predictable
Answer» In gases, there is no appreciable molecular interaction.

Discussion

19854.	When we raise the temperature of a body, the molecules and atoms move with greater kinetic enery. Assume that "the temperature" is the manifestation of only the kinetic energy is atomic and subatomic levels and no mass change (excess//defect) occurs due to heating. Now a solid material is supplied with heat at a constant rate. The temperature of the material is changing with the heat input as shown in the graph. `BC` and `DE` are parallel to the Heat-input axis In `BC` and `DE` A. kinetic energy increasesB. potential energy increasesC. kinetic energy decreasesD. potential energy remains constant
Answer» In `BC` and `DE` temperature remains constant `rArr K.E.` remains constant `rArr` Heat goes to increasing the `P.E.`

Discussion

19855.	The figure that is not a direct manifestation of the quantum nature of atoms
Answer» Answer is (1) Photoelectric effect (option 2), atomic spectrum (option 3) and Black body radiations (option 4) may be explained by quantum theory. As on increasing temperature, all the values of internal energy becomes possible, it is not directly explained from quantum theory.

19855.

The figure that is not a direct manifestation of the quantum nature of atoms

Answer»

Answer is (1)

Photoelectric effect (option 2), atomic spectrum (option 3) and Black body radiations (option 4) may be explained by quantum theory. As on increasing temperature, all the values of internal energy becomes possible, it is not directly explained from quantum theory.

Discussion

19856.	For the following Assertion and Reason, the correct option isAssertion (A) : When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.Reason (R) : The equilibrium constant of Cu2+ (aq) + S2- (aq) ⇌ CuS(s) is high because the solubility product is low.(1) Both (A) and (R) are true and (R) is the explanation for (A)(2) Both (A) and (R) are false(3) (A) is false and (R) is true (4) Both (A) and (R) are true but (R) is not the explanation for (A)
Answer» Answer is (4) Both (A) and (R) are true but (R) is not the explanation for (A) Slow or fast process is kinetic parameter but extent less or more is thermodynamic parameter.

19856.

For the following Assertion and Reason, the correct option isAssertion (A) : When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.Reason (R) : The equilibrium constant of Cu2+ (aq) + S2- (aq) ⇌ CuS(s) is high because the solubility product is low.(1) Both (A) and (R) are true and (R) is the explanation for (A)(2) Both (A) and (R) are false(3) (A) is false and (R) is true (4) Both (A) and (R) are true but (R) is not the explanation for (A)

Answer»

Answer is (4) Both (A) and (R) are true but (R) is not the explanation for (A)

Slow or fast process is kinetic parameter but extent less or more is thermodynamic parameter.

Discussion

19857.	At least how many half-lives should elapse for a `1^(st)` order reaction `Ato` products so that the reaction is at least `95%` completed? `(log2=0.3)`A. 4B. 5C. 6D. 7
Answer» Correct Answer - B `underset(0%)(100)overset(t_((1)/(2)))tounderset(50%)(50)overset(t_((1)/(2)))tounderset(75%)(25)overset(t_((1)/(2)))to` `underset(87.5%)(12.5)overset(t_((1)/(2)))tounderset(93.75%)(6.25)overset(t_((1)/(2)))tounderset(96.875%)(3.125)`

Discussion

19858.	For the reaction `2A+BtoC` with the rate low `(d[C])/(dt)=k[A]^(1)[B]^(-1)` and started with A and B in stoichiometric proportion.Which is/are true ?A. unit of k is `Ms^(-1)`B. [A],[B] and [C] all will be linear functions of timeC. [C]=2ktD. [C]=kt
Answer» Correct Answer - A,B,C `{:(" ",2A" " +,B" " to,C),(t=0,2a,a,0),(t=t,2a-2x,a-x,x):}` `(d[C])/dt=k2(a-x)(a-x)^(-1)=2kimplies intd[c]=intk dtimplies [C]=2kt` unit of k=`Ms^(-1)` `[A]=2(a-x) and [C]=x` `[B]=(a-x)`

Discussion

19859.	For a certain reaction `Ato` products, the `t_(1//2)` as a function of `[A]_0` is given as below: `{:([A]_0(M),0.1,0.025),(t_(1//2),100,50):}` Which of the following is true :A. The order of `1/2`B. `t_(1//2)`would be `100sqrt10` min for `[A]_0=1` MC. The order is 1D. `t_(1//2)`would be `100` min for `[A]_0=1` M
Answer» Correct Answer - A,B `100prop(0.1)^(t-n)` `50prop(0.025)^(1-n)` Divide `2=4^(1-n)` `2=2^(2-2n) implies " " 2-2n=1` `n=1/2` `100 prop (0.1)^(1//2) implies t^(1//2)prop(1)^(1//2)` Divide `t_(1//2)/100=(1/0.1)^(1//2)` `t_(1//2)=100sqrt10` min.

Discussion

19860.	Extra pure `N_2` can be obtained by heatingA. `NH_(3)` with calcium hypochloriteB. `NH_(4)Cl+NaNO_(3)`C. `(NH_(4))_(2)Cr_(2)O_(7)`D. `Ba(N_(3))_(2)`
Answer» Correct Answer - 4 `Ba(N_(3))_(2)(s)overset(Delta)rarrBa(s)+3N_(2)(g)`

Discussion

19861.	A graph between `log t_((1)/(2))` and log a (abscissa), a being the initial concentration of A in the reaction For reaction `Ato`Product, the rate law is : A. `(-d[A])/(dt)=K`B. `(-d[A])/(dt)=K[A]`C. `(-d[A])/(dt)=K[A]^2`D. `(-d[A])/(dt)=K[A]^3`
Answer» Correct Answer - C `t_(1//2)=Ka^(1-n)`,n being order K=Rate constant log `t_(1//2)=log K+(1-n) log a` 1-n=-1 n=2

Discussion

19862.	A gaseous reaction `A_(2)(g) rarr B(g) + (1)/(2) C(g)` shows increase in pressure form `100 mm` to `120 mm` in `5 min`. What is the rate of disappearance of `A_(2)` ?A. 4B. 8C. 16D. 2
Answer» Correct Answer - A `{:(,A_2(g)to,B(g)+,1/2C(g)),(t=0,100,0,0),(t=5,100-p,p,p//2),("At" "t"=5 "min",,underset(p=20)(100+p//2=110),):}` rate of disappearence of `A_2=20/5=4`

Discussion

19863.	For a `1^(st)` order reaction (gaseous) (constant V, T) : `aAto(b-1)B+1 C` (with `bgta`) the pressure of the system rose by `50(b/a-1)` % in a time of 10 min. The half life of the reaction is therefore.A. 10 minB. 20 minC. 30 minD. 40 min
Answer» Correct Answer - A `{:(aA,to,(b-a)B,+C),(t=0,P_0,0,0),(t=t,P_3x,((b-a)x)/a,x/a):}` Total pressure `P_0-x+b/ax=P_0+(b/a-1) 1/2 P_0` `P_0+(b/a-1)x=P_0+(b/a-1)P_0/2` `x=P_0/2` `P_A=P_0-x=P_0-P_0/2=P_0/2` `P_A` reduces to half in 10 min, so `t_(t//2)`=10 min

Discussion

19864.	`[Cr(NH_(3))_(6)][Cr(SCN)_(6)]` and `[Cr(NH_(3))_(2) (SCN)_(4)][Cr(NH_(3))_(4) (SCN)_(2)]` are the examples of what type of isomerism?A. Ionisation isomerismB. Linkage isomerismC. Coordination isomerismD. Solve isomerism
Answer» Correct Answer - C These are co-ordianates isomers, which s arises due to exchange ofligands between positive and negative ions.

Discussion

19865.	For a certain reaction the variation of rate constant with temperature is given by the equation `ln k_(t) = lnk_(0) + ((ln 3)t)/(10) (t ge 0^(@)C)` The value of temperature coefficient of the reaction isA. 0.1B. `1.0`C. 10D. 3
Answer» Correct Answer - D `k_t/k_o=(TC)^(t-0//10)` Taking log gives `"log"_e k_t-"log"_e k_0=t/10 "log"_e(TC)` `implies "In" k_t="In" k_o+(("In"(TC))/10)t` Comparison indicates `("In"(TC))/10=("In"3)/10implies TC=3`

Discussion

19866.	The correct IUPAC name `[Co(NH_(3))_(3)(NO_(2))_(3)]` isA. Triammine trinitro N cobalt (III)B. Triammine trinitro N cobalt (II)C. Triammine cobalt (III) nitriteD. Triammine trinitro N cobaltate (III)
Answer» Correct Answer - a The IUPAC na e of `[Co(NH_(3))_(3)(NO)(2)_(3)]` is triammine trinitro N cobalt (III)

Discussion

19867.	The correct IUPAC name of `[Co(NH_(3))_(3)(NO_(2))_(3)]`A. Triammine trinitrito - N cobalt (III)B. Triammine trinitrito - N cobalt (II)C. Triammine cobalt (III) nitriteD. Triammine trinitrito-N cobaltate (III)
Answer» Correct Answer - A IUPAC name of `[Co(NH_(3))_(3)(NO_(2))_(3)]` is triamminetrinitritio-N-cobalt (III).

Discussion

19868.	Potassium dichromate is a good oxidizing agent, in acidic medium the oxidation state of chromium changes byA. 2B. 3C. 4D. 5
Answer» Correct Answer - B It acts as oxidising agent in acidic medium by gain of six electrons and oxidation state of Cr `Cr_(2)O_(7)^(2-) + 14H^(+) + 6e^(-) to 2Cr^(3+) + 7H_(2)O`

Discussion

19869.	In fig, PA, QB and RC are each perpendicular to AC. If x = 8 cm and z = 6 cm, then y is equal to(a) 56/7 cm(b) 7/56 cm(c) 25/7 cm(d) 24/7 cm
Answer» Correct option is (d) 24/7 cm

Discussion

19870.	The only radioactive element among the lanthanoids isA. gadoliniumB. holmiumC. promethiumD. neodymium
Answer» Correct Answer - c Among the lanthanioids promethium is the only radioactive element

Discussion

19871.	The increasing order of basic strength of Cl–, CO32-, CH3COO-, OH-, F- is :
Answer» Correct option: (a) Explanation: More is the acidic character, lesser is basic character of conjugate base.

19871.

The increasing order of basic strength of Cl–, CO32-, CH3COO-, OH-, F- is :

Answer»

Correct option: (a)

Explanation:

More is the acidic character, lesser is basic character of conjugate base.

Discussion

19872.	What are Strong electrolyte ? Give an examples.
Answer» Those ionic conductors which are completely ionized in aqueous solution are called as strong electrolyte. Ex . Na⁺ Cl^– , K⁺ Cl^– , etc. For strong electrolyte the value of degree of dissociation is 100%. i.e. α = 1 Ex : (a) Strong acid → H₂SO₄, HCl, HNO₃ HClO₄, H₂SO₅, HBr, HI (b) Strong base → KOH, NaOH, Ba(OH)₂ CsOH, RbOH (c) All Salts → NaCl, KCl, CuSO₄ ..........

19872.

What are Strong electrolyte ? Give an examples.

Answer»

Those ionic conductors which are completely ionized in aqueous solution are called as strong electrolyte.

Ex . Na⁺ Cl^– , K⁺ Cl^– , etc.

For strong electrolyte the value of degree of dissociation is 100%. i.e. α = 1

Ex :

(a) Strong acid → H₂SO₄, HCl, HNO₃ HClO₄, H₂SO₅, HBr, HI

(b) Strong base → KOH, NaOH, Ba(OH)₂ CsOH, RbOH

(c) All Salts → NaCl, KCl, CuSO₄ ..........

Discussion

19873.	Which one is greater α1 or α2 for the following equation :(i) NH4OH + H2O → α1 (ii) NH4OH + D2O → α2
Answer» Dielectric constant of H₂O is more than that of D₂O , so α₁ > α₂

Discussion

19874.	Which one of the following is strongest acid ?A. `H_2S`B. `H_2Se`C. `H_2O`D. `H_2Te`
Answer» Correct Answer - (d) ``HNO_(2)+HNO_(3) rarrNO_(2)+H_(2)O` Hecne `NO_(2)` mixd anhydride of Te-H bond strength , acts as the strongest acid.

Discussion

19875.	The mixed anhydride of nitrous and nitric acid is.A. ` N_2O`B. ` NO_2`C. `NO`D. `N_2O_5`
Answer» Correct Answer - B When oxidation state of central atom is same , with the decrease in elctornegativity of central atom acidic character decreases. Hence `H_(3)PO_(4)` is most acidic . `H_(3)PO_(4) ft H_(3) AsO_(4) gt H_(3) SbO_(4) gtH_(3) BiO_(4)`

Discussion

19876.	Of the follwing , the most acidic is .A. ` H_3 PO_4`B. ` H_3AsO_4`C. `H_3SbO_4`D. `H_3BiO_4`
Answer» Correct Answer - A `CH_(3)CH_(2)NO_(2) overset(HNO_(2))(rarr) CH_(3)underset("nitrolic acid")underset((blue))underset(" N-OH")underset(\|\|)(C)-ON_(2) overset(NaOH)(rarr) CH_(3)underset((red))underset(" NONa")underset(\|\|)C-NO_(2)` `overset(CH_(3))overset(\|)(CH_(3)CHNO_(2))overset(HNO_(2))(rarr)-overset(CH_(3))overset(\|)underset(("blue"))underset("pseudonitrol")underset(" N=O")underset(\|)(C)-NO_(2) overset(NHO_(2))(rarr)underset((blue))("noreaction")` `(CH_(3))_(3)CNO overset (HnO_(2))(rarr)`.

Discussion

19877.	Assertion `:-` Adding inert gas at equilibrium to dissociation of `PCL_(3)` at constant pressure increases the degree of dissociation. Reason `:-` Since degree of dissociation `x` `alphasqrt(v)`A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertiion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False
Answer» Correct Answer - A

Discussion

19878.	Assertion `:-` `K_(c)` for process `2H_(2)O(l)hArr2H_(2)O_((g))+O_(2(g))`may be written as `:K_(c)=[H_(2)]^(2)[O_(2)]` Reason `:-` Concentration of pure liquid is fixed and cannot vary (Taken as `1`)A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertiion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False
Answer» Correct Answer - A

Discussion

19879.	Write the IUPAC name of the following coordination compounds:I. K4[Fe(CN)6]II. Ni(CO)4III. K2[Pt(Cl)6]IV. CO(NH3)3V. Fe4[Fe(CN)6]3
Answer» I. K₄[Fe(CN)₆] - Potassium hexacyanoferate((II) II. Ni(CO)₄- Tetracarbonyl Nickel III. K₂[Pt(Cl)₆] - Potassium tetra cyano platinate (III) IV. CO(NH₃)₃- Tri Tramine Cobalt (II) V. Fe₄[Fe(CN)₆]₃- Iron hexa cyanoferrate (Il)

19879.

Write the IUPAC name of the following coordination compounds:I. K4[Fe(CN)6]II. Ni(CO)4III. K2[Pt(Cl)6]IV. CO(NH3)3V. Fe4[Fe(CN)6]3

Answer»

I. K₄[Fe(CN)₆] - Potassium hexacyanoferate((II)

II. Ni(CO)₄- Tetracarbonyl Nickel

III. K₂[Pt(Cl)₆] - Potassium tetra cyano platinate (III)

IV. CO(NH₃)₃- Tri Tramine Cobalt (II)

V. Fe₄[Fe(CN)₆]₃- Iron hexa cyanoferrate (Il)

Discussion

19880.	Which of the following is related to steroid ? (A) Vitamin E (B) Vitamin K (C) Vitamin B (D) Vitamin D
Answer» Correct answer is (D) Vitamin D

Discussion

19881.	Which of the following is the sweetest sugar ? (A) Sucrose (B) Fructose (C) Maltose (D) Lactose
Answer» Correct answer is (B) Fructose

Discussion

19882.	State Werner's coordination theory.
Answer» The first systematic attempt at explaning the formation, reactions, structure and bonding of a coordination compound was made by A. Werner His theory postulated the use of two types of linkages (primary and secondary) by a metal atom/ion in a coordination. In the modern language of chemistry these linkages are recognised as the ionisable (ionic) and non-ionisable (covalent) bonds respectively.

Discussion

19883.	In which of the following alkylation is possible ? (A) In primary amine only (B) In secondary amine only (C) In tertiary amine only (D) In both primary and secondary amines
Answer» Correct answer is (D) In both primary and secondary amines

Discussion

19884.	Find total number of species in which Zn metal is soluble under oridnary condition (R.T.). `H_(2)O,"dil".H_(2)SO_(4),"conc". H_(2)SO_(4),"dil".HNO_(3),"conc".HNO_(3),"dil". HCl,NaOH(aq),AgNO_(3)(aq.),CuSO_(4)(aq.)`
Answer» Correct Answer - 8 `Zn+"dil".H_(2)SO_(4)rarrZnSO_(4)(aq)+H_(2)uarr` `Zn+"conc".H_(2)SO_(4)rarrZnSO_(4)(aq)+SO_(2)uarr` `Zn+"dil". HNO_(3)rarrZn(NO_(3))_(2)(aq)+N_(2)Ouarr` `Zn+"conc."HNO_(3)rarrZn(NO_(3))_(2)(aq)+NO_(2)uarr` `Zn+"dil". HClrarrZnCl_(2)(aq)+H_(2)rarr` `Zn+NaOHrarrNa_(2)Zn(OH)_(4)(aq)+H_(2)uarr` `Zn+AgNO_(3)rarrZn(NO_(3))_(2)+Agdarr` `Zn+CuSO_(4)rarrZnSO_(4)+Cudarr`

Discussion

19885.	x = Number of compounds for which formaldehyde is necessary as reactant to obtained them by aldol reaction or condensation `HO-CH_(2)-CH_(2)-CHO`
Answer» Correct Answer - 4 `III, VI, VII and VIII`

Discussion

19886.	The functional group of primary amine is – (A) – NH - (B) – NH2 (C) NH3 (D) NH4+
Answer» Correct answer is (B) – NH₂

Discussion

19887.	Acetamide on reaction with Br2 and NaOH gives – (A) Acetone (B) Methylamine (C) Acetaldehyde (D) Ammonia
Answer» Correct answer is (B) Methylamine

Discussion

19888.	Ethylamine on reaction with nitrous acid gives – (A) C2H5OH (B) CH3COOH (C) C2H5NO2 (D) None of these
Answer» Correct answer is (A) C₂H₅OH

Discussion

19889.	Match the statement given in Column I with the phenomenon given in Column II.Column I Column II(i) Dispersion medium moves in an (a) Osmosiselectric fleld(ii) Solvent molecules pass through semi (b) Electrophoresispermeable membrane towards solvent side(iii) Movement of charged colloidal particles (c) Electro osmosisunder the inuence of applied electric potentialtowards oppositely charged electrodes(iv) Solvent molecules pass through semi permeable (d) Reverse osmosismembranes towards solution side
Answer» (i) (c) (ii) (d) (iii) (b) (iv) (a)

Discussion

19890.	CuSO4 is colourless while CuSO4.5H2O is coloured. Why ?
Answer» CuSO₄ does not has any ligand, so splitting of d-orbital take place while CuSO₄.5H₂O has water ligand.

Discussion

19891.	How is stability of coordination compound determined in aqueous solution ?
Answer» By using stability constant. More stability constant, more stability.

Discussion

19892.	What is the difference between inner and outer orbital complexes ?
Answer» Inner sphere complex : When d-orbital of inner shell take part in hybridisation. Outer sphere complex : When d-orbital of outermost shell take part in hybridisation.

Discussion

19893.	Calculate the mass of hydrochloric acid in 200 cm3 of 0.2 N solution of it. What volume of this acid solution will react exactly with 25 cm3 of 0.14 N solution of sodium hydroxide?
Answer» Normality of hydrochloric acid = 0.2; Eq. mass of hydrochloric acid = 36.5 Mass of hydrochloric acid in one dm³ of the solution is given by W = N × E = 0.2 × 36.5 g ∴ mass of hydrochloric acid in 200 cm³ of the solution = 0.2 x 36.5/5 = 1.46 g V₁ x N₁ = V₂ x N₂ Acid Base Substituting we have V₁ × 0.2 = 25 × 0.14 ∴ V₁ = 25 x 0.14/0.2 = 17.5 cm³

19893.

Calculate the mass of hydrochloric acid in 200 cm3 of 0.2 N solution of it. What volume of this acid solution will react exactly with 25 cm3 of 0.14 N solution of sodium hydroxide?

Answer»

Normality of hydrochloric acid = 0.2;

Eq. mass of hydrochloric acid = 36.5

Mass of hydrochloric acid in one dm³ of the solution is given by

W = N × E = 0.2 × 36.5 g

∴ mass of hydrochloric acid in 200 cm³ of the solution = 0.2 x 36.5/5 = 1.46 g

V₁ x N₁ = V₂ x N₂

Acid Base

Substituting we have V₁ × 0.2 = 25 × 0.14

∴ V₁ = 25 x 0.14/0.2 = 17.5 cm³

Discussion

19894.	Give example of a material used for making semi permeable membrane for carrying out reverse osmosis.
Answer» Cellulose acetate, potassium ferrocyanide, etc. are used as semipermeable membrane for carrying out reverse osmosis.

Discussion

19895.	what happens when gelatin is mixed with gold SOL.
Answer» When gelatin is mixed with gold sol then Gold sol is stabilized and no coagulating takes place.

Discussion

19896.	How is lake test for aluminium ion based upon adsorption ?
Answer» [Hint : A_l2O₃.xH₂O has the capacity to adsorb the colour of blue litmus from the solution.

Discussion

19897.	correct order of basicity is
Answer» in A lone pair are in sp^2 hybridisation,B lone pair are in sp^3 hybridisation C lone pair are in resonance of the molecule

Discussion

19898.	Consider the ΔG°f and ΔH°f (kJ/mol) for the following oxides. Which oxide can be most easily decomposed to form the metal and oxygen gas?(a) ZnO (ΔG° = - 318.4, ΔH° = - 348.3)(b) Cu2O(ΔG° = - 146.0, ΔH° = - 168.8)(c) HgO (ΔG° = - 58.5, ΔH° = - 90.8)(d) PbO (ΔG° = - 187.9, ΔH° = - 217.3)
Answer» Correct option (c) HgO (ΔG° = - 58.5, ΔH° = - 90.8) Oxide with lowest –ve ΔG°

19898.

Consider the ΔG°f and ΔH°f (kJ/mol) for the following oxides. Which oxide can be most easily decomposed to form the metal and oxygen gas?(a) ZnO (ΔG° = - 318.4, ΔH° = - 348.3)(b) Cu2O(ΔG° = - 146.0, ΔH° = - 168.8)(c) HgO (ΔG° = - 58.5, ΔH° = - 90.8)(d) PbO (ΔG° = - 187.9, ΔH° = - 217.3)

Answer»

Correct option (c) HgO (ΔG° = - 58.5, ΔH° = - 90.8)

Oxide with lowest –ve ΔG°

Discussion

19899.	Which of the following instruments has a property of quick response time?1. Analogue instrument2. Electrical instrument3. Electronic instrument4. Mechanical instrument
Answer» Correct Answer - Option 3 : Electronic instrument Explanation: Measurement generally involves using an instrument as a physical means of determining a quantity or variable. The instrument serves as an extension of human faculties and enables the man to determine the value of an unknown quantity that unaided human faculties cannot measure. An instrument may be defined as a device for determining the value or magnitude of a quantity or variable. Measuring instruments, and formal test methods which define the instrument's use, are the means by which the variables and the relations between variables are obtained The various types of measuring instruments are: Analogue Instrument Electrical Instrument Electronic Instrument Mechanical Instrument Electronic Instruments have the fastest response time among all. The majority of modern scientific and industrial measurements require very rapid responses. The mechanical and electrical instruments and systems cannot fulfill these requirements. There is a requirement of decreasing the response time and also the detection of dynamic changes in certain parameters. This has led to the design of today's electronic instruments and their associated circuitry. These instruments involved vacuum tubes or semiconductor devices. The present-day practice is to use semi-conductor devices owing to their many advantages over their vacuum tube counterparts. Since in electronic devices the only movement involved is that of electrons and the inertia of electrons is very small, the response time of these devices is extremely small. Electronic instruments make it possible to build analogue and digital computers without which the modern developments in science and technology are virtually impossible. Computers require a very fast time response and it is only possible with the use of electronic instruments. The mathematical processing of signals, such as summation, differentiating, and integrating is possible with electronic measurements.

19899.

Which of the following instruments has a property of quick response time?1. Analogue instrument2. Electrical instrument3. Electronic instrument4. Mechanical instrument

Answer» Correct Answer - Option 3 : Electronic instrument

Explanation:

Measurement generally involves using an instrument as a physical means of determining a quantity or variable. The instrument serves as an extension of human faculties and enables the man to determine the value of an unknown quantity that unaided human faculties cannot measure. An instrument may be defined as a device for determining the value or magnitude of a quantity or variable. Measuring instruments, and formal test methods which define the instrument's use, are the means by which the variables and the relations between variables are obtained

The various types of measuring instruments are:

Analogue Instrument
Electrical Instrument
Electronic Instrument
Mechanical Instrument

Electronic Instruments have the fastest response time among all.

The majority of modern scientific and industrial measurements require very rapid responses. The mechanical and electrical instruments and systems cannot fulfill these requirements. There is a requirement of decreasing the response time and also the detection of dynamic changes in certain parameters.
This has led to the design of today's electronic instruments and their associated circuitry. These instruments involved vacuum tubes or semiconductor devices. The present-day practice is to use semi-conductor devices owing to their many advantages over their vacuum tube counterparts. Since in electronic devices the only movement involved is that of electrons and the inertia of electrons is very small, the response time of these devices is extremely small.
Electronic instruments make it possible to build analogue and digital computers without which the modern developments in science and technology are virtually impossible. Computers require a very fast time response and it is only possible with the use of electronic instruments. The mathematical processing of signals, such as summation, differentiating, and integrating is possible with electronic measurements.

Discussion

19900.	Reaction of ‘magnesium’ with air is
Answer» The reaction of magnesium with air is an exothermic reaction as magnesium burns with dazzling brilliance in the air forming white shiny magnesium oxide with the evolution of a lot of heat. 2Mg + O₂ → 2MgO + heat

19900.

Reaction of ‘magnesium’ with air is

Answer»

The reaction of magnesium with air is an exothermic reaction as magnesium burns with dazzling brilliance in the air forming white shiny magnesium oxide with the evolution of a lot of heat.

2Mg + O₂ → 2MgO + heat

Discussion

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Reaction of ‘magnesium’ with air is