InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 91951. |
5g of Nacl is dissolved in 1000g of water. If the density of the resulting solution is 0.997 g per "cc", calculate the molality, molality, normality and mole fraction of the solute. |
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Answer» Solution :Mole of NaCl `=(5)/(58.5)=0.0854` (mol.wt.of `NaCl=58.5`) By definition : Molality `=("moles")/("wt.of solvent in grams")xx1000` `=(0.0854)/(1000)xx1000=0.0854m` VOLUME of the solution `=("wt in grams")/("density in grams"//"cc")=(1005)/(0.997)"cc"` `=1008mL=1.008` litres Again by definition molarity `=("moles")/("volume of solution in litres")=(0.0854)/(1.008)=0.085M` `:.` normality = `0.085N` (for NaCl, eq.wt.=mol.wt.) Further, `underset(("PER"1000g))("moles of" H_(2)O)=(1000)/(18)=55.55` (Supposing 1mL=1g for water having density `1g//mL`) TOTAL moles = moles of NaCl `+` moles of `H_(2)O` `=0.0854+55.55=55.6409` Mole fraction of NaCl=`("moles of" NaCl)/("total moles")=(0.0854)/(55.6409)` `=1.53xx10^(-3)` |
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| 91952. |
9*65D C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus, obtained is completely converted into a grignard reagents. What is the number of moles of grignard reagent obtained? |
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Answer» Solution :`MgCl_(2)overset((AQ))(to)MgCl^(2)+(aq)+2Cl^(-)(aq)` `Mg^(2+)(aq)+UNDERSET((2xx96500C))(2e)^(-)toMg(s)` (At cathode) `2xx29500C` of charge deposite MG metal =1mol `9*65C` of charge deposite Mg metal `=((1mol))/((2xx96500C))xx(9*65C)=5xx10^(-5)mol` `R-X+underset(1mol)(Mg)("Anhyd. ether")toR-underset(1mol)(MG)-X` `therefore` No of moles of GRIGNARD REAGENT obtained `=5xx10^(-5)`mol. |
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| 91953. |
5g of a sample of bleaching powder is treated with excess acetic acid and KI solution. The liberated I_(2) required 50 mL of N/10 hypo. The % of available chlorine in the sample. |
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Answer» `W_(Cl_(2))` = 0.1775 g `% Cl_(2) = 0.1775 xx 100 = 3.55%` |
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| 91954. |
5g H_(2) is allowed to react with 14 g N_(2) for the following reaction. N_(2)(g)+3H_(2)(g)rarr2NH_(3)(g) What mass of H_(2) will be left unreached at the end of reaction? |
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Answer» Mass before reaction =Mass after reaction `(5+14)=(17+x)` x=2g |
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| 91955. |
96500C electricity is passed through CuSO_(4) the amount of copper precipitated is |
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Answer» 0.25 mole 2xx96500C deposits 1 mole of COPPER 96500C deposits 0.5 mole of copper. |
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| 91956. |
5f-level is successively filled up in : |
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Answer» Lanthanides |
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| 91957. |
5Br_((aq))+BrO_(aq)^(-)+6H_((aq))^(+)to3Br_(2(aq))+3H_(2)O_(l) in this reaction (Delta[br^(-)])/(Deltat)=4.2xx10^(-3) mol L^(-1)S^(-1) so calculate (Delta[Br_(2)])/(Deltat) i.e. rate of foramtion of Br_(2) |
| Answer» SOLUTION :`(5)/(3)xx4.2xx10^(-3) mol L^(-1) S^(-1)` | |
| 91958. |
5A to Product In above reaction, half-life period is directly proportional to initial concentration of reactant. The initial rate of reaction is 400 mol lit^(-1)" min"^(-1). |
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Answer» |
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| 91959. |
96500 coulombs deposit 107.9 g of Ag from its soluton. If e = 1.6 xx 10^(-19) coulomb, calculate the number of electrons per mole of electrons |
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Answer» 96500 |
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| 91960. |
96500 Coulomb will deposite "…………………." of metal. |
| Answer» SOLUTION :ONE GRAM EQUIVALENT MASS | |
| 91961. |
5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is : |
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Answer» 0.1 Moles of water `=(90)/(18)=5` MOLE fraction of NaCl `=(0.1)/(5+0.1)=0.0196` |
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| 91962. |
96500 coulombs corresponds to the charge on how many electrons- |
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Answer» `1.6 XX 10^(19)` |
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| 91963. |
5.85 g of NaCl is dissolved in 90 g water what is the mole fraction of NaCl ? |
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Answer» SOLUTION :MOLE fraction , X =( 5.85/ 8.5)/(90/ 18)+( 8.85/58.5) = 0.1/6 + 0.1 = 0.02 |
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| 91964. |
9.65C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus, obtained is completely converted into a Grignard reagent. The number of moles of the Grignard reagent obtained is |
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Answer» `5xx10^(-4)` 9.65 coulombs of electric current deposits `(9.65)/(96500)=1.2xx10^(-3)` g of Mg `THEREFORE` No. of moles of GRIGNARD reagent obtained `=(1.2xx10^(-3))/(24)=5xx10^(-5)` moles |
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| 91965. |
58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water. Identify the correct statement regarding the elevation of boiling point (b.pt.) of the resulting solutions. |
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Answer» NACL solution will show HIGHER elevation of b.pt. For water `rArr 1000 mL = 1000 g` Molality of `NaCl =(w//M.W)/(W(Solvent) xx 1000` `= (58.5 // 58.5)/(1000) xx 1000 =1m` Molality of gulcose `=(180//180)/(1000) xx 1000 =1m` if For `NaCl =2` , i for glucose = 1 `Delta T_b` for `NaCl GT Delta T_b` for glucose |
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| 91966. |
9.65 C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus obtained is completely converted into a Grignard reagent. The number of moles of Grignard reagent formed is : |
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Answer» `5XX10^(-4)` `2xx96500" C"` of CHARGE form Mg =1 mol 9.65C of charge form Mg `=((1mol)xx(9.65" C"))/(2xx(96500" C"))=5xx10^(-5)mol` `Mg-=RMgX` MOLES of Grignand reagent formed `=5xx10^(-5)mol`. |
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| 91967. |
58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water. Identify the correct statement regarding the elevation of boiling point (b.pt.) of the resulting solutions |
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Answer» NaCl solution will show higher ELEVATION of b.pt. For water `rarr 1000 ML = 1000 G` Molality of `NaCl=(w//M.W.)/("W(SOLVENT)")xx1000` `=(58.5//58.5)/(1000)xx1000=1m` Molality of glucose `=(180//180)/(1000)xx1000=1m` i for NaCl = 2, i for glucose = 1 `Delta T_(b)` for `NaCl gt Delta T_(b)` for glucose |
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| 91968. |
9.65 C of electric current is passed through fused anhydrous MgCl_(2) .The magnesium metal thus obtained is completely converted into a Grignard reagent. The number of moles of Grignard reagent obtained is |
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Answer» `5 xxl0^(-4)` MOLES |
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| 91969. |
5.85 g of NaCI is dissoloved in water and the solution is made upto 0.5 litre. The molarity of solution is: |
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Answer» 1 M ` =((5.85g)//(58.5g MOL^(-1)))/((0.5 L))` `=((0.1 mol))/((0.5 L))=0.2 mol L^(-1)=0.2 M` |
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| 91970. |
5.85 g NaCl is dissovled in 1L water. The number of ions of Na^(+) and Cl^(-) in 1 mL of this solution will be: |
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Answer» `6.02xx10^(19)` `=("Mass")/("MOLAR mass")=(5.95)/(58.5)=0.1` Number of ions `(Na^(+)+Cl^(-))` in 1L `=2xx01xx6.023xx10^(23)` `=12.046xx10^(22)` Number of ions in 1mL `=(12.046xx10^(22))/(1000)=1.2xx10^(20)` |
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| 91971. |
9.65 C electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus obtained is completely converted into a Grignard reagent. The number of moles of the grignard reagent obtained is |
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Answer» `5xx10^(-4)` 2F, i.e., `2xx96500C` deposit Mg=1mole `therefore9.65C` will deposit Mg `=(1)/(2xx96500)xx9.65=5xx10^(-5)` MOLE `RX xx MgtoRMgX` 1 mole of Mg forms G.R.=1 mole `therefore5xx10^(-5)` of Mg will FORM G.R. `=5xx10^(-5)` mole. |
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| 91972. |
58 ml of N/5 H_(2)SO_(4) are used to neutralize ammonia given by 1 g of organic compound. Percentage of nitrogen in the compoundis |
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Answer» `34.3` `= (1.4 xx 1 xx 58)/(1 xx 5)= 16.2` |
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| 91973. |
965 amp current is passed through molten metal chloride for one minute and 40 seconds during electrolysis. The mass of metal deposited is 9 gm at the cathode. The valency of metal atom (at. wt = 27) is |
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Answer» 4 |
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| 91974. |
9.65 amp current is passed through moltenAlCl_(3) for one minute forty seconds during electrolysis. The mass of Aldeposited is 0.09g at the cathode. What is the valency of Al |
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| 91975. |
._(95)Am^(241) and ._(90)Th^(234) belongs respectively to |
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Answer» `4n + 4n +1` radioactive disintegration series In `._(90)Th^(234)` the massno. Division by four gives a residue of 2. |
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| 91976. |
5.8 g of non - volatile, non - electrolyte solute was dissolved in 100 g of carbon disuiphide (CS_(2)). The vapour pressure of the solution was found to be 190 mm of Hg. Calculate molar mass of the solute. Given : Vapour of pure CS_(2) is 195 mm of Hg and molar mass of CS_(2) is 76g//mol. |
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Answer» Solution :MASS of SOLUTE`(W_(B))=5.8 g`. Mass of solvent i.e., `CS_(2)` is `(W_(A))=100g` Vapour pressure of solution `(RHO)=190` mm of Hg. Vapour pressure of pure solvent `(P_(A))=195` mm of Hg Molar mass of pure solvent`CS_(2)(M_(A))=76 gmol^(-1)`. `M_(B)(p_(A)-p)/(p_(A)^(0))=(W_(B)M_(A))/(M_(B)W_(A))` `(195-190)/(195)=(5.8xx76)/(M_(B)xx100)` `(5)/(195)=(5.8xx76)/(M_(B)xx100)` `M_(B)=(5.8xx76xx195)/(5xx100)=1719 gmol^(-1)` |
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| 91977. |
9.5g of MgCl_(2) is dissolved in 100 g of water . The freezing point of the solution is -4.836^(@)C Then . |
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Answer» Degree of dissociation of `MgCl_(2)` is `80%` |
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| 91978. |
56g of N_(2) ( molar mass = 28) are mixed with 44g of CO_(2) ( molar mass = 44) and the pressure of the resulting gaseous mixture is 3 atm. The partial pressure of N_(2) in the mixture is : |
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Answer» i. 1 atm Moles of `CO_(2) = ( 44)/( 44) = 1 ` Mole fraction of `N_(2) = ( 2)/( 2+1) = ( 2)/(3)` Partial PRESSURE of `N_(2) = ( 2)/(3) xx 3 = 2 atm` |
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| 91979. |
9.5 g of CH_2 FCOOHis dissolved in 500 g of water. The depression in the freezing point observed is 1.0^@C . Calculate the van't Hoff factor and dissociation constant of fluroacetic acid. |
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Answer» Solution :Given `w_2 = 19.5 , w_1 = 500 g, K_f = 1.86 K kg "mol"^(-1) ,(Delta T_f)_(OBS) = 1.0^@C` ` therefore M_2 `(OBSERVED ) `= (1000K_f w_2)/(w_1 Delta T_f) = (1000 XX 1.86 xx 19.5)/(500 xx 1.0) = 72.54 g "mol"^(-1)` `M_2`(calculated) for `CH_2FCOOH = 14 + 19 + 45 = 78 g "mol"^(-1)` van.t hoff factor (i)` = ((M_2)_(cal))/((M_2)_(obs)) = (78)/(72.54) = 1.0753` Calculation of dissociation constant : suppose degree of dissociation at the given concentration is `alpha` ` therefore i = (C(1+alpha))/(C ) =1 + alpha` or ` alpha = i-1 = 1.0753 -1=0.0753` Dissociation constant of the ACID is calculated as under : `K_alpha = ([K_2FCOO^(-)][H^+])/([CH_2FCOOH]) =(Calpha.Calpha)/(C(1-alpha)) = (C.alpha^2)/(1- alpha)` Concentration `C = (19.5)/(78) xx 1/500 xx 1000 = 0.5M` ` therefore K_alpha = (C alpha^2)/(1- alpha) = ((0.5)(0.0753)^2)/(1-0.0753) = 3.07 xx 10^(-3)` |
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| 91980. |
56g of gaseous nitrogen and 64g of gaseous sulphur dioxide are mixed together in a 6L vessel. If the total pressure of the mixture is 3 atm, what will be the partial pressure of nitrogen in the mixture ? |
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Answer» 3 atm |
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| 91981. |
95% ethyl alcohol can be converted to 100 % ethyl alcohol by the following |
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Answer» MAGNESIUM chloride |
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| 91982. |
5600 ml of O_(2) is obtained by electrolysis at STP, then how much Ag is obtained by same electricity ? (atomic mass of Ag=108) |
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Answer» `5.4gm` `(W_(Ag))/(108)xx1=(W_(O_(2)))/(M_(O_(2)))xx4""(2H_(2)O to O_(2)+4H^(+)+4e^(-))` `(W_(Ag))/(108)xx1=(W_(O_(2)))/(M_(O_(2)))xx4` `(W_(Ag))/(108)=(1)/(4)xx4""therefore W_(Ag)=108gm`. |
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| 91983. |
._(92)U^(235) + n rarrfission product + neutron + 3.20 xx 10^(-11) J. The energy released when 1g of ._(92)U^(235) undergoes fission is |
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Answer» `12.75 xx 10^(8) kJ` `:.` ENERGY released `= 3.2 xx 10^(-11) xx (6.023 xx 10^(23))/(235) J` `= 8.21 xx 10^(1) J = 8.2 xx 10^(7) kJ` |
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| 91984. |
._(92)U^(235) belongs to group III B of periodic table. If it loses one alpha-particle, the new element will belong to group |
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Answer» I B |
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| 91985. |
5.6 litres of methane (CH_(4)) gas are ignited in oxygen gas. Calculate the number of moles of CO_(2) formed. |
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Answer» |
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| 91986. |
""_(92)U^(235) belongs IIIB of the periodic table. If it losses one alpha particle, the new element will belong to group |
| Answer» Solution :III B is group 3. On LOSING `alpha`- PARTICLE, the NEW element will be in group 1 i.e. I A. | |
| 91987. |
56 g of nitrogen and 8 g of hydrogen gas are heated in a closed vessel. At equilibrium 34 gof ammonia are present. The equilibrium number of moles of nitrogen, hydrogen and ammonia are respectively |
| Answer» ANSWER :C | |
| 91988. |
""_(92)U^(235)belong to group IIIB to periodic table. If it loses one alpha particle, the new element will belong to the group |
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Answer» VB |
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| 91989. |
56 g of nitrogen and 8 g of hydrogen gas are heated in a cloed vessel. At equilibrium, 34 g of ammonia are present. The equilibrium number of moles of nitrogen, hydrogen and ammonia are respectively |
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Answer» 1, 2, 2 8 g of `H_(2)` = 8/2 = 4 moles, 34 g of `NH_(3)` = 34/17 = 2 moles. `{:(,N_(2),+,3H_(2),iff,2NH_(3)),("INITIAL","2 moles",,"4 moles",,),("At eqm.","2 - 1 mole",,"4 - 3 moles",,"2 moles"),(,"= 1 mole",,"= 1 mole",,):}` |
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| 91990. |
5.6 g of but-2-ene is taken ina 250 mL round bottom flask. 3.7 g of conc, HCl is added to it and the resultant mixture is stirred till the reaction is complete . The practical yield of the reaction is 50% , Calculate the mass of the product formed. |
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Answer» 0.35 g |
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| 91991. |
""_92^238Uis radioactive and it emits alpha and beta particles to form ""_82^206Pb . Calculate the numberof alpha and betaparticles emitted in this conversion. An ore of ""_92^238Uis found to contain ""_92^238U and""_82^206Pbin the weight ratio of 1:0.1. The half-life period ""_92^238U is 4.5 xx 10^9 years. Calculate the age of the ore. |
| Answer» SOLUTION :`8, 6, 7.098 XX 10^8 ` YEARS | |
| 91992. |
5.6 g of an organic compound on burning with excess of oxygen gave 17.6g of CO_(2) and 7.2 g H_(2)O. The organic compound is: |
| Answer» Answer :B | |
| 91993. |
._(92)^(238)U emits 8 alpha-particles and 6-beta-particles. The neutron/proton ratio in the product nucleus is |
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Answer» 60/41 Number of protons = 82, Number of neutrons = 124 Neutron/proton RATIO in the PRODUCT nucleus `= (124)/(82) = (62)/(41)` |
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| 91994. |
5.6 g of a steel sample containing sulphur impurity was burnt in oxygen. SO_2 , so produced, was then oxidised to sulphate by H_2O_2solution to which 30 mL of 0.004 M NaOH solution had been added. 22.48 mL of 0.024 M HCl was required to neutralize the base remaining after oxidation reaction. Calculate percentage of S in the given sample of steel. |
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Answer» Solution :`SO_2 + H_2O_2 + 2OH^(-) = SO_4^(2-) + 2H_2O` m mol of S = MMOL of `SO_2 = 1/2 XX ` m mol of `OH^(-)= (30 xx 0.04) - 22.48 xx 0.024)` |
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| 91995. |
._(92)^(238)U by successive radioactive decay changes to ._(82)^(206)Pb. A sample of uranium ore was analysed and found to contain 1.0g of .^(238)U and 0.1g of .^(206)Pb. Assuming that all .^(206)Pb hasaccumulated due to decay of .^(238)U, find the age of the ore (half life of .^(238)U=4.5xx10^(9) yrs). |
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Answer» SOLUTION :Number of MOLES of `.^(238)U = (1)/(238)` Number of moles of `.^(206)Pb = (0.1)/(206)` Applying the relationship, `t = (2.303/(lambda) log [1 + (.^(206)Pb)/(.^(238)U)]` `= (2.303)/(0.693) xx 4.5 xx 10^(9) log [1 + ((0.1)/(206))/((1)/(238))] = 7.098 xx 10^(8)` YEARS |
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| 91997. |
""_(92)^(238)U by successive radioactive decay changes to ""_(82)^(206)Pb. A sample of uranium ore was analysed and found to contain 1.0 gm of .^(238)U and 0.1gm of .^(206)Pb. Assuming that all the .^(206)Pb has accumulated due to decay of .^(238)U, find the age of the ore (half-life of .^(238)U=4.5xx10^(9)years). |
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Answer» |
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| 91998. |
5.5 mg of nitrogen gas dissolves in 180 g of water at 273 K and one atm pressure due to nitrogen gas.The mole fraction of nitrogen in 180 g of water at 5 atm nitrogen pressure is approximately |
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Answer» `1XX10^(-6)` `n_(N_(2))=(5.5xx10^(-3))/(28)=1.96xx10^(-4)` at 1 atm Now,p `prop` mole fraction then at 5 atm, the mole fraction will increase 5 TIMES. HENCE, `5xx1.96xx10^(-4)= 9.8xx10^(-4)~~10xx10^(-4)= 1.0xx10^(-3)` |
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| 91999. |
""_(92)^(238) U is the element of III B group , it undergoes decay as follows , ""_(92) ^(238) U overset(- alpha)(to) A overset(-alpha)(to) B overset(-beta)(to) C Which of the following statements is/are correct ? |
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Answer» A will be of III B group |
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| 92000. |
5.39of a mixture of FeSO_(4). 7H_(2)Oand anhydrous ferricsulphaterequires80 mL of 0.125 N permangnatesolution for complete conversion to ferricsulphate. Calculate the individual weights of eachcomponentof the original mixture . |
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Answer» Solution :FERRUS ulphatepresentin the mixtureto oxidisedto ferricsulphate by permagnate solution . LET the weight of ferrous sulphatebe x gram . m.e of `FeSO_(4).7H_(2)O`= m.e of permagnate solution ` = 0.125 xx 80 = 10 ` ` :. ` eq. of `FeSO_(4) . 7H_(2) O = 10/1000 ""...(EQN . 3)` ` :. ` WT . of `FeSO_(4) .7H_(2)O = eq xx eq.wt ` ` = 10/1000 xx 278` ` = 2.78 g` and wt. of `Fe_(2) (SO_(4))_(3) = (5.39 - 2.78 ) g ` ` = 2.61 g ` |
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