52671 + Interview Questions in Chemistry in Class 11

1.	A metal M reaccts with nitrogen to give nitride which on reaction with water produces ammonia gas. Metal M can be
Answer» Na K LI Rb Solution :`6Li+N_(2) OVERSET(Delta)to 2Li_(3)N` `Li_(3)N+3H_(2)Oto3LiOH+NH_(3)`

Discussion

2.	A metal (M) produces a gas( N) on reacting with alkalies like NaOH and KOH. Same gas is produced when the metal reacts with dilute sulphuric acid. Gas(N) reacts with another toxic gas (P) to form methonol at high temperature and pressure. (N) also reacts with metals like (Q) to form electrovalent hydrides. Identify M,N,N and Q.
Answer» Solution :The available information SUGGESTS than the metal (M) is most probably ZINC (Zn). The chemical reactions involved are listed. 1. `underset((M))(Zn)+2NaOHtoNa_(2)ZnO_(2)+underset(N)(H_(2))` `Zn+H_(2)SO_(4)("DIL.")toZnSO_(4)+underset((N))(H_(2))` 2. `underset((N))(2H_(2))+underset((P))(CO)overset("700K, 200atm ")underset("Co-catalyst ")(to)underset("Methanol")(CH_(3)OH)` `underset((Q))(2Na)+H_(2)to2NaH`

Discussion

3.	A metalMof equivalent mass E froms an oxide of molecular formula M_(x)O_(y). The atomic mass of the metal is given by the correct equation
Answer» `2E(y//x)` xyE E/y y/E Answer :A::B

Discussion

4.	A certain metal is present in the soil, plants, bones, egg shelts, sea shells and coral. It is also used to remove oxygen from molten steel and its hydroxide is used to detect Co_2. The metal is
Answer» Al Mg Ca Na Answer :C

Discussion

5.	A metal, M forms chlorides in +2 and +4 oxidation states. Which of the following statement about these chlorides is correct ?
Answer» `MCl_(2)` is more volatile than `MCl_(4)` `MCl_(2)` is more soluble in anyhydrous ethanol than `MCl_(4)`. `MCl_(2)` is more ionic than `MCl_(4)` `MCl_(2)` is more easily HYDROLYSED than `MCl_(4)`. SOLUTION :Compounds in the lower OXIDATION STATES are moe ionic than those in the HIGHER oxidation states. Thusm `MCl_(2)` is more ionic than `MCl_(4)`.

Discussion

6.	A metal is irradiated with a radiation of wavelength 300 nm. Then photo electrons found to have velocity of 3.7 xx 10^5 m/s. When a graph is drawn between K.E of photo electrons and frequency of radiation a straight line is obtained cutting X-axis. Difference between incident frequency and threshold frequency is
Answer» `9.4xx10^(13)` Hz `8.5xx10^(22)` Hz `9.4xx10^(12)` Hz `8.4xx10^(10) Hz` Solution :`upsilon - upsilon_0 =(6.625xx10^(-19))/(6.625xx10^(13)) -9.09 XX 10^(14)` `=9.4xx10^(23) Hz`

Discussion

7.	A metal is irradiated with a radiation of wavelength 300 nm. Then photo electrons found to have velocity of 3.7 xx 10^5 m/s. When a graph is drawn between K.E of photo electrons and frequency of radiation a straight line is obtained cutting X-axis. The value of X-intercept
Answer» `9XX10^4 `Hz `10.2xx10^5` Hz `8.6xx10^5` Hz `9xx10^(14)` Hz Solution :`E = (hc)/(lambda) = 6.625 xx 10^(-19) J , KE =6.23xx10^(-20)J` W`= E- KE= 6.002 xx 10^(-19)` `hv_0 = 6.002xx10^(-19) impliesv_0 = 9.09xx10^(14) Hz`

Discussion

8.	A metal is irradiated with a radiation of wavelength 300 nm. Then photo electrons found to have velocity of 3.7 xx 10^5 m/s. When a graph is drawn between K.E of photo electrons and frequency of radiation a straight line is obtained cutting X-axis. What is the K.E. of photo electrons
Answer» `6.23xx10^(-20)` J `6.25 xx 10^(-22)` J `6.625xx10^(-18)` J `6.625 xx10^(-19)` J Solution :K.E `=1/2 mv^2 = 6.23xx10^(-20) J`

Discussion

9.	A metal ion M^(3+) loses 3 electrons, its oxidation number will become ____
Answer» `+3` `+6` 0 `-3` SOLUTION :`M^(+3)toM^(+6)+3E^(-)` By releasing `3e^(-),M^(+3)` BECOMES `M^(+6)`

Discussion

10.	A metal ion M^(3+) loses 3 electrons its oxidation number will be
Answer» `+3` `+6` 0 `-3` SOLUTION :`M^(3+)rarrM^(6+)+3E^(-)`

Discussion

11.	A metal ion M^(3+) after loss of three electrons in a reaction will have an oxidation number equal to
Answer» ZERO `+2` `+3` `+6` ANSWER :D

Discussion

12.	A metal has a fcc lattice. The edge of the unit cell is 404 pm. The density of the metal is2.72 " g cm"^(-3) . The molar mass of the metal is( N_(A) , Avogardro's constant =6.02 xx 10^(23) mol^(-1))
Answer» ` 40g mol^(-1)` `30 g mol^(-1)` `27 g mol^(-1)` `20 g mol^(-1)` Solution :DENSITY , ` p= ( Z xx M)/(a^(3) xx N_(A) xx 10^(-30))` ` therefore2.72 = ( 4 xx M)/(( 404)^(3) xx ( 6.02 xx 10^(23)) xx 10^(-30))` `orM = ( 2.72 xx (404)^(3) xx 6.02 xx 10^(23) xx 10^(-30))/4` ` = 27 g mol^(-1)`

Discussion

13.	A metal has a fcc lattice. The edge length of the unit cell is 404 pm.The density of the metal is 2.72 "g cm"^(-3). The molar mass of the metal is (N_A , Avogadro's constant =6.02xx10^23 "mol"^(-1))
Answer» `"40 g mol"^(-1)` `"30 g mol"^(-1)` `"27 g mol"^(-1)` `"20 g mol"^(-1)` SOLUTION :Density , `rho=(ZxxM)/(a^3xxN_Axx10^(-30))` `therefore 2.72=(4xxM)/((404)^3xx(6.02xx10^23)xx10^(-30))` or `M=(2.72xx(404)^3xx6.02xx10^23xx10^(-30))/4` `=27 "g mol"^(-1)`

Discussion

14.	A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm^(-3)? The molar mass of the metal is (N_(A)" Avogadro's constant" = 6.02times10^(23) mol^(-1))
Answer» `40" g "MOL^(-1)` `30" g "mol^(-1)` `27" g "mol^(-1)` `20" g "mol^(-1)` SOLUTION :`"Density " rho = (ZtimesM)/(a^(3)timesN_(A)times10^(-30))` `therefore 2.72 = (4timesM)/((404^(3))times(6.02times10^(23))times10^(-30))` `therefore M = (2.72times(404)^(3)times(6.02times10^(23))times10^(-30))/4` =`27 g"" mol^(-1)`

Discussion

15.	A metal forms a chloride with the formula MCl_2.Formula of Phosphoric acid is H_3PO_4. Formula ofthe Phosphate of the metal is
Answer» `M_3PO_4` `MPO_4` `M_3(PO_4)_2` `M_2PO_4` ANSWER :C

Discussion

16.	A metal crystallizes with a face-centred cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is
Answer» 288 PM 408 pm 144 pm 204 pm Solution :For fcc lattice, `r=a/(2SQRT2)`=0.3535 a =0.3535 x 408 pm =144 pm `therefore` Diameter=2r =288 pm

Discussion

17.	Ametal crystallizes witha face- centred cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is
Answer» 288 PM 408 pm 144 pm 204 pm SOLUTION :For fcc,LATTICE , ` R = a/(2SQRT2) = 0.3535 a ` = `0.3535 xx 408 "pm" = 144 "pm"` Diameter = 2 r = 288 pm.

Discussion

18.	A metal crystallizes into two cubic phases, face- centred cubic (fcc) and body -centred cubic (bcc)whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of fcc and bcc.
Answer» Solution :Denstiy ` (p) = ( Z XX M)/(a^(3) xx N_(0)) ` ForZ = 4,a = 3.5 Å= 3.5 Å= 3.5 ` xx 10^(-8)`cm . ` p_("fcc")= (4xxM) /((3.5 xx 10^(-8))xx N_(0)) ` for bcc, Z =2 , a = 3.0 Å = 3.0 ` xx 10^(-8)`cm `p_("bcc")= ( 2xx M)/((3.0 xx10^(-8))^(3) xx N_(0)) therefore p_("fcc")/p_("bcc") = ( 4XX (3.0 xx 10^(-8))^(3))/(2xx (3.5 xx10^(-8))^(3) ) =1.259`

Discussion

19.	A metal crystallizes into two cubic phases , face-centred cubic (fcc) and body -centred cubic (bcc) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratioof the densities of fcc and bcc.
Answer» Solution :DENSITY `(RHO)=(ZxxM)/(a^3xxN_0)` For fcc, Z=4,a=3.5 Å =`3.5xx10^(-8)` cm `therefore rho_"fcc"=(4xxM)/((3.5xx10^(-8))xxN_0)` For bcc, Z=2, a=3.0 Å =`3.0xx10^(-8)`cm `therefore rho_"bcc"=(2xxM)/((3.0xx10^(-8))^3xxN_0) therefore rho_"fcc"/rho_"bcc"=(4XX(3.0xx10^(-8))^3)/(2XX(3.5xx10^(-8))^3)=1.259`

Discussion

20.	A metal crystallize in a body centered cubic lattice (bcc) with the edge of the unit cell 5.2Å. The distance between the two nearest neighour is
Answer» `10.4 Å` `4.5Å` `5.2Å` `9.0Å` ANSWER :B

Discussion

21.	A metal crystallises into two cubic phases , face-centred cubic (FCC) and body-centred cubic (BCC) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of FCC and BCC
Answer» Solution :`rho_"FCC"/RHO"BCC"=Z_"FCC"/(a^3)_"FCC"XX(a^3)_"BCC"/Z_"BCC"=(4xx(3.0)^3)/(2xx(3.5)^3)=1.26`

Discussion

22.	A metal crystallises in a face centred cubic structure. If the edge length of the unit cell is 'a' the closest approachbetween the two atoms in the metallic crystal will be
Answer» `sqrt2a` `a/sqrt2` 2a `2sqrt2a` Solution :For the fcc STRUCTURE, nearest NEIGHBOUR DISTANCE (d)=`a/sqrt2`.

Discussion

23.	A metal crystallises in a face centred cubic structure. If the edge length of the unit cell is 'a' the closest approach betweenthe twoatoms in the metallic crystal will be
Answer» `sqrt2a` `a/sqrt2` 2a `2SQRT2 a ` Solution :For the FCC structure, nearture, nearest neighbour DISTANCE ` (d) = a/sqrt2`

Discussion

24.	A metal crystallises in a bcc lattice. Its unit cell edge length is about 300 pm and its molar mass is about 50g mol^(-1). What would be the density of the metal ("in" g"" cm^(-3)).
Answer» 3.1 6.2 9.3 12.4 Solution :`a=300"pm", Z=2`(for bcc unit cell) `M=50 g"" mol^(-1)` `"Density", rho(ZtimesM)/(N_(A)TIMESA^(3)times10^(-30))g""cm^(-3)` `=(2times50)/(6.02times10^(23)times(300)^(3)times10^(-30))` `=100/(6.02times27times10^(-1))` `=1000/(6.02times27)=6.15 g cm^(-3)`

Discussion

25.	A metal (atomic mass 50) has a body centred cubic crystal structure. The density of the metal is 5.96 "g cm"^(-3). Find the volume of the unit cell (N_O=6023xx10^23 "atoms mol"^(-1))
Answer» SOLUTION :MASS of the unit cell = Mass of one ATOM x No. of atoms PRESENT in the unit cell `=(50/(6.023xx10^23)g)xx2` [For BCC, Z=2] Volume of the unit cell=`"Mass"/"Density"=(50xx2)/(6.023xx10^23)gxx1/(5.96 g cm^(-3))=2.786xx10^(-23) cm^(3)`

Discussion

26.	A metal (atomic mass = 50)has a body centred cubic crystal structure.The density of the metal is5.96 " g cm"^(-3) 1 find the volume of the unit cell = ( N_(0)= 6.023 xx 10^(23)atoms"mol"^(-1) )
Answer» SOLUTION :Mass of the unit cell = Mass of one ATOM ` xx ` No. of atoms present in the unit cell. `= ((50)/(6.023xx10^(23))G)xx2 [ For BCC, Z =2] ` Volume of the unit cell = `("mass")/("Density")= ( 50xx2)/(6.023 xx 10^(23)) g xx 1/((5.96 " g CM"^(-3)) = 2.786 xx 10^(-23)" cm" ^(3)`

Discussion

27.	(A): Meso tartaric acid is optically inactive (R): Meso tartaric acid has no asymmetric carbon
Answer» Both (A) and (R) are true and (R) is the CORRECT explanation of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is FALSE (A) is false but (R) is true Solution :(A) is true but ( R ) is false

Discussion

28.	(a). Mention the most abundant and least abudant alkaline earth metal in the earth's crust. (b).Mention at least five important properties of alkaline earth metals which increase from Be to Ba. c. Arrange alkaline earth metals in order of decreasing hydration enthalpy. d. Ca, Sr and Ba generally form ionic compounds. why? e. Mention colours of Ca,Ba and Sr in flame test.
Answer» Solution :(a). Amongst the alkaline earth metals, the most abundant is calcium and the least abundant is radium in the earth's crust. (b). Five IMORTANT PROPERTIES of alkaline earth metals which increas from `Be` to `Ba` are: i. size, ii. Metallic property, iii. reducing nature, vi. tendency to form peroxide, v. reactiveity C. Hydration enthalpy: `Be^(2+)gtMg^(2+)gtCa^(2+) GT SR^(2+)gtBa^(2+)` d. `Ca,Sr` and `Ba` generally form ionic compounds due to their low ionisation enthalpy. e. `{:("Elements",Ca,Sr,Ba),(Flame,Brick,Crimson,"Apple"),(colour,red,red,green):}`

Discussion

29.	(a) Menthol is a crystalline substance with peppermint taste. A.6.2% solution of menthol in cyclohexane freezes at -1.95^(@)C. Determine the formula mass of menthol. The freezing point and molar depression constant of cyclohexane are 6.5 ^(@)C and 20.2Km ^(-1), respectively. (b) State Henry's Law and mention its two important applications. (c ) Which of the following has higher boiling point and why ? 0.1M NaCl or 0.1 M Glucose
Answer» Solution :(a)` Delta T_(f) = K _(f) m= (W _(B))/(M _(B))xx (1000)/(W _(A))` `8.45 =20.3 K kg mol ^(-1) xx (6.2 g )/( M _(B)) xx (1000)/(93.8kg` ` M _(B)=158 mol ^(-1)` (b) Henry.s Law: The SOLUBILITY of gas in a LIQUID is directly proporational to the pressure of the gas. Applications: 1. Solubility of `CO_(2)` is increased at high pressurre. 2. Mixture of He and `O_(2)` are used by deep sea divers because he is less soluble than nitrogen. (c ) `0.1M NaCl,` because it dissociates in solution and furnishes GREATER number of particles PER unit volume while glucose being a non-electrolyte does not dissociate.

Discussion

30.	(A) Meniscus of a liquid disappears at the critical temperature. (R) Density of liquid and its gaseous phase become equal at the critical temperature.
Answer» If both A and R are CORRECT and R is the correct explanation of A If both A and R are correct but R is not the correct explanation of A If A is correct but R is incorrect If A is incorrect but R is correct Answer :A

Discussion

31.	A measured temperature on Fahrenheit scale is 200""^(@)F. What will this reading be on celsius scale ?
Answer» `40""^(@)C` `94""^(@)C` `93.3""^(@)C` `30""^(@)C` Solution :There are only three SCALES to measure temperature `""^(@)C, ""^(@)F` and . The K is the SI unit. The temperature on TWO scales are related to each other by the following EQUATION. `""^(@)F= 9/5 t""^(@)C+32` APPLYING the values in above equation, `200-32= 9/5 t""^(@)C` `:.9/5 t""^(@)C= 168` `:. t""^(@)C= (168xx5)/(9) = 93.3""^(@)C`

Discussion

32.	A maximum 10^(-x) moles of MgCl_(2) couldbe dissolbed in one litre of a solution containing 0.1 M NH_(3) and 0.01 M NH_(4)^(+), without causing precipitation of Mg(OH)_(2), what is the value of 'x'? (K_(a) of NH_(4)^(+) = 10^(-8), K_(sp) of Mg(OH)_(2) is 10^(-16))
Answer» SOLUTION :N//A

Discussion

33.	[A] Match the solutes in Column-I with th van't Hoff factors in Column-II : {:(,"Column-I",,"Column-II"),("(a)",K_(4)[Fe(CN)_(6)],"(p)",1+alpha),("(b)",Al_(2)(SO_(4))_(3),"(q)","Greater than 1"),("(c)",NH_(2)-overset(overset(O)("\|\|"))(C)-NH_(2),"(r)",(1+4alpha)),("(d)",CaCl_(2),"(s)",1):} alpha= Degree of ionization.
Answer» ANSWER :(a-Q,R);(b-q,r);(c-s);(d-p,q)

Discussion

34.	[A] Match the following : {:((a),"Terramycin",(p),"Disinfectant",),((b),"Bithional",(q),"Antacid",),((c ),"Sodium perbenzoate",(r),"Anticeptic",),((d),"Chlorine",(s),"Soap",),((e),"Potassium stearate",(t),"Antibiotic",),((f),"Renitidine",(u),"Milk bleaching agent",):} [B] {:((a),"Phenelzine",(p),"Antiseptic",),((b),"Chloramphenicol",(q),"Anti-fertility drug",),(( c),"Dettol",(r),"Antihistamine",),((d),"Salversan",(s),"Tranquillizer",),((e),"Bromopheniramine",(t),"Antimicrobial",),((f),"Mestranol",(u),"Antibiotic",):} [C] {:((a),"Antagonists",(p),"Transferring of nerves message",),((b),"Agonists",(q),"Communicate message between two neurons and that between neurons to muscles",),((c),"Neurotransmitters",(r),"Inhibit activities of enzymes",),((d),"Chemical messenger",(s),"Imitate the natural messenger",),((e),"Inhibitors",(t),"Crucial to body communication process",),((f),"Receptors",(u),"Bind to the receptor site and inhibit its natural sunction",):} [D]
Answer» SOLUTION :[A] (a-t), (B-r), (C-u), (d-p), (e-s), (f-q) [B] (a-s), (b-u), (c-p), (d-t), (e-r), (f-q) [C] (a-u), (b-s), (c-p), (c-p), (d-t), (e-r), (f-t) [D] (a-s), (b-u), (c-p), (d-p), (d-t), (e-r), (f-q)

Discussion

35.	(A): The Mass, volume and pressure are extensive properties. (R): Extensive properties depend upon the amount of the substance.
Answer» Both A and R are TRUE and R is the CORRECT EXPLANATION Both A and R are true but R is not the correct explanation of A A is true but R iş false A is false but R is true Answer :A

Discussion

36.	A manomter is connected to a gas containing bulb. The open arm reads 43.7 cm whereas the arm connected to the bulb reads 15.6 cm. If the baremetric pressure is 743 mm mercury, what is the pressure of gas in bar ?
Answer» Solution :Difference of mercury LEVELS in the two arms `=43.7-15.6 cm=28.1" cm"` As LEVEL in the limb connected to the gas bulb is lower than that of open limb, this means PRESSURE of gas is more than the atmospheric pressure. `:. `Pressure of the gas in the bulb =Barometric pressure+Difference of mercury levels =74.3 cm +28.1 cm=102.4 cm `=(102.4)/(76)ATM=(102.4)/(76)xx1.01325" bar"=1.365 " bar "`

Discussion

37.	A manifestation of surface tension is :
Answer» RISE of liquid in a capillary tube Spherical SHAPE of liquid drops Upward movement of WATER in soils All the above Solution :S.T give capillary rise and spherical shape.

Discussion

38.	A man weighs 72.15kg and want to fly in the sky with the aid of balloons itself weighing 20 kg and each containing 50 moles of H_(2) gas at 0.05 atm and 27^(@)C 1.25g//litre how many such types of ballons he is needed to fly in the sky ? .
Answer» ANSWER :3

Discussion

39.	A major constituent of portland cement is?
Answer» Silica Alumina Iron oxide Magnesia Solution :EXCEPT LIME `(50-60%)` the MAJOR CONSTITUENT of CEMENT is silic `(20-25%)`

Discussion

40.	A major class of organic halides that are thought to pose a threat to stratospheric ozone are _________.
Answer» ANSWER :A::B::C

Discussion

41.	A magician took yellow colured solution in one test tube and added a colourless solution Into It and announced the fun of getting red colour. Then he added red coloured solution into it and announced the fun of colour becoming lighter. What chemicals he musthave used and explain how all this might have happened ?
Answer» Solution :He MUST have taken a ferric SALT , e.g., ferric nitrate solution (yellow) and added thicoyanate e.g., KSCN solution (colourless). The product formed is ferric sulphocynided complex, `[Fe(SCN)^(2+)` (red colour) . Then he must have added potassium ferrosulphocyanide which gives `[Fe(SCN)]^(2+)` IONS and the equilibrium shifts backward forming back ferric salt and thiosyanate so that intensity of red colour DECREASES.

Discussion

42.	A Magic solution was prepared by a Kota Teacher such that : A(g)+10(aq)toA.10(aq),"" DeltaH=-10 kJ//mol [Magic solution] For 1 mole of H_(2)O added to this Magic solution enthalpy of dilution is -5 kJ//mol, for 2nd mole it becomes-(5)/(2) kJ//mol, for 3rd mole it becomes -(5)/(2^(2)) kJ//mol and so on. To mark the celebration rank-1 of IIt JEE-2016, KOTA CLASSES asked the top ranker to add a very large amount of water to this Magic solution. The hat energy released is 40% converted to useful work of buring fire crackers for celebration. Find the magnitude of useful work obtained ("in kJ"//"mol") from such Magic solution containing 1 mole of A.
Answer» ANSWER :4

Discussion

43.	A macroscopic particle of mass 100 g and moving at velocity of 100 cms^(-1) will have a de Broglie wavelength of………
Answer» `66xx10^(29)cm` `6.6xx10^(-30)cm` `6.6xx10^(-31)cm` `6.6xx10^(-32)cm` Solution :`m=100g=100xx10^(3)KG` `v=100cm s^(-1)=100xx10^(-2)m s^(-1)` `gammah/(MV)` `(6.626XX10^(34)JS^(-1))/(100xx10^(-3)kGxx100xx10^(-2)ms^(-)` `6.626xx10^(-31)ms^(-1)` =`6.625xx10^(-31)ms^(-1)`

Discussion

44.	(A) Lyophilic colloids such as starch, gelatin, etc, act as protective colloids . (R) Protective power of lyophilic colloids is expressed in terms of gold number.
Answer» IF both (A) and (R) are correct and (r) is the correct EXPLANATION for (a). If both (a) and (r) are correct but (r) is not the correct explanation for (a). IF (a) is correct but (r) is INCORRECT. If (a) is incorrect but (r) is correct. Answer :B

Discussion

45.	A m^(3) vessel at STP has oxygen gas. How many moles of oxygen are present?
Answer» Solution :22.4 at STP= 1mol `1 m^(3) = 1000L` NUMBER of moles of OXYGEN`=1M^(3)XX(1000L)/(1m^(3))xx(1mol)/(22.4L) = (1000)/(22.4) = 44.6`

Discussion

46.	Given an example of meta-directing group.
Answer» ANSWER :F

Discussion

47.	A litre of sea water weighing about 1.05 kg contains 5 mg of dissolved oxygen (O_(2)). Express the concentration of dissolved oxygen in ppm.
Answer» Solution :`("mass of DISSOLVED solid")/("Mass of water") xx 10 ^(6)` ` ( 5XX 10 ^(-3) g)/(1. 05 xx 10 ^(3) g )xx 10 ^(6) = 4.76 PPM`

Discussion

48.	(A) Litmus is not used in Lassaigne's test. (R) It generally forms covalent compounds.
Answer» If both assertion and REASON are CORRECT and reason is the correct explanation of the assertion If both assertion and reason are correct but reason is not the correct explanation of the assertion If assertion is correct but reason is incorrect If assertion is incorrect but reason is correct ANSWER :A

Discussion

49.	Assertion: Lithium resembles magnesium in its properties Reason: The ratio of ionic charge to "(Ionic radius)"^2 is almost same for Li^+ and Mg^(2+)
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is FALSE (A) is false but (R) is true Answer :A

Discussion

50.	(A): Lithium reacts with water more vigorously than sodium (R): Lithium possesses small size and very high hydration energy The correct answer is
Answer» (A) is CORRECT but (R) is not correct (A) is not correct but (R) is correct Both (A) and (R ) are correct and (R) is the correct EXPLANATION of (A) Both (A) and (R) are correct but (R) is not the correct explanation of (A) ANSWER :B

Discussion

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A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm^(-3)? The molar mass of the metal is (N_(A)" Avogadro's constant" = 6.02times10^(23) mol^(-1))

A metal forms a chloride with the formula MCl_2.Formula of Phosphoric acid is H_3PO_4. Formula ofthe Phosphate of the metal is

A metal crystallizes with a face-centred cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is

Ametal crystallizes witha face- centred cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is

A metal crystallizes into two cubic phases, face- centred cubic (fcc) and body -centred cubic (bcc)whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of fcc and bcc.

A metal crystallizes into two cubic phases , face-centred cubic (fcc) and body -centred cubic (bcc) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratioof the densities of fcc and bcc.

A metal crystallize in a body centered cubic lattice (bcc) with the edge of the unit cell 5.2Å. The distance between the two nearest neighour is

A metal crystallises into two cubic phases , face-centred cubic (FCC) and body-centred cubic (BCC) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of FCC and BCC

A metal crystallises in a face centred cubic structure. If the edge length of the unit cell is 'a' the closest approachbetween the two atoms in the metallic crystal will be

A metal crystallises in a face centred cubic structure. If the edge length of the unit cell is 'a' the closest approach betweenthe twoatoms in the metallic crystal will be

A metal crystallises in a bcc lattice. Its unit cell edge length is about 300 pm and its molar mass is about 50g mol^(-1). What would be the density of the metal ("in" g"" cm^(-3)).

A metal (atomic mass 50) has a body centred cubic crystal structure. The density of the metal is 5.96 "g cm"^(-3). Find the volume of the unit cell (N_O=6023xx10^23 "atoms mol"^(-1))

A metal (atomic mass = 50)has a body centred cubic crystal structure.The density of the metal is5.96 " g cm"^(-3) 1 find the volume of the unit cell = ( N_(0)= 6.023 xx 10^(23)atoms"mol"^(-1) )

(A): Meso tartaric acid is optically inactive (R): Meso tartaric acid has no asymmetric carbon

(A) Meniscus of a liquid disappears at the critical temperature. (R) Density of liquid and its gaseous phase become equal at the critical temperature.

A measured temperature on Fahrenheit scale is 200""^(@)F. What will this reading be on celsius scale ?

A maximum 10^(-x) moles of MgCl_(2) couldbe dissolbed in one litre of a solution containing 0.1 M NH_(3) and 0.01 M NH_(4)^(+), without causing precipitation of Mg(OH)_(2), what is the value of 'x'? (K_(a) of NH_(4)^(+) = 10^(-8), K_(sp) of Mg(OH)_(2) is 10^(-16))

(A): The Mass, volume and pressure are extensive properties. (R): Extensive properties depend upon the amount of the substance.

A manomter is connected to a gas containing bulb. The open arm reads 43.7 cm whereas the arm connected to the bulb reads 15.6 cm. If the baremetric pressure is 743 mm mercury, what is the pressure of gas in bar ?

A manifestation of surface tension is :

A man weighs 72.15kg and want to fly in the sky with the aid of balloons itself weighing 20 kg and each containing 50 moles of H_(2) gas at 0.05 atm and 27^(@)C 1.25g//litre how many such types of ballons he is needed to fly in the sky ? .

A major constituent of portland cement is?

A major class of organic halides that are thought to pose a threat to stratospheric ozone are _________.

A macroscopic particle of mass 100 g and moving at velocity of 100 cms^(-1) will have a de Broglie wavelength of………

(A) Lyophilic colloids such as starch, gelatin, etc, act as protective colloids . (R) Protective power of lyophilic colloids is expressed in terms of gold number.

A m^(3) vessel at STP has oxygen gas. How many moles of oxygen are present?

Given an example of meta-directing group.

A litre of sea water weighing about 1.05 kg contains 5 mg of dissolved oxygen (O_(2)). Express the concentration of dissolved oxygen in ppm.

(A) Litmus is not used in Lassaigne's test. (R) It generally forms covalent compounds.

Assertion: Lithium resembles magnesium in its properties Reason: The ratio of ionic charge to "(Ionic radius)"^2 is almost same for Li^+ and Mg^(2+)

(A): Lithium reacts with water more vigorously than sodium (R): Lithium possesses small size and very high hydration energy The correct answer is