PYQSide ExamsMy practice

Equilibrium · Question 86

AIPMT 2005MCQMedium📈 Topic in 38% papers+4−1
1

H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because

  1. presence of HCl decreases the sulphide ion concentration
  2. solubility product of group II sulphides is more than that of group IV sulphides
  3. presence of HCl increases the sulphide ion concentration
  4. sulphides of group IV cations are unstable in HCl.

Answer

(1) presence of HCl decreases the sulphide ion concentration

Solution

H2S 2H+ + S2-

As per NCERT, HCl supplies the common ion H+, which suppresses the ionisation of H2S (common ion effect).

⇒ The concentration of S2- ions becomes very low.

∵ Group II sulphides (CuS, PbS, CdS …) have very low Ksp, their ionic product still exceeds Ksp and they precipitate.

∵ Group IV sulphides (ZnS, MnS, NiS, CoS) have higher Ksp, their ionic product stays below Ksp and they do not precipitate.

∴ The presence of HCl decreases the sulphide ion concentration.

Answer: (1)

AIPMT 2005

Keep practising — Equilibrium

2

Equilibrium constants K1 and K2 for the following equilibria: NO(g) + 12O2(g) K1 NO2(g) and 2NO2(g) K2 2NO(g) + O2(g) are related as

  1. K2 = 1/K12
  2. K2 = K12
  3. K2 = 1/K1
  4. K2 = K1/2
AIPMT 2005
3

The solubility product of a sparingly soluble salt AX2 is 3.2 10-11. Its solubility (in moles/L) is

  1. 5.6 10-6
  2. 3.1 10-4
  3. 2 10-4
  4. 4 10-4
AIPMT 2004
4

The rapid change of pH near the stoichiometric point of an acid-base titration is the basis of indicator detection. pH of the solution is related to ratio of the concentrations of the conjugate acid (HIn) and base (In-) forms of the indicator by the expression

  1. [In-][HIn] = pKIn - pH
  2. [HIn][In-] = pKIn - pH
  3. [HIn][In-] = pH - pKIn
  4. [In-][HIn] = pH - pKIn
AIPMT 2004
5

The equilibrium constants of the following are N2 + 3H2 2NH3; K1 N2 + O2 2NO; K2 H2 + 12O2 H2O; K3 The equilibrium constant (K) of the reaction : 2NH3 + 52O2 2NO + 3H2O will be

  1. K2K33/K1
  2. K2K3/K1
  3. K23K3/K1
  4. K1K33/K2
AIPMT 2003
6

The reaction quotient (Q) for the reaction N2(g) + 3H2(g) 2NH3(g) is given by Q = [NH3]2[N2][H2]3. The reaction will proceed from right to left if

  1. Q = Kc
  2. Q < Kc
  3. Q > Kc
  4. Q = 0
AIPMT 2003
7

The solubility product of AgI at 25 C is 1.0 10-16 mol2 L-2. The solubility of AgI in 10-4 N solution of KI at 25 C is approximately (in mol L-1)

  1. 1.0 10-16
  2. 1.0 10-12
  3. 1.0 10-10
  4. 1.0 10-8
AIPMT 2003
8

Reaction BaO2(s) BaO(s) + O2(g); H = +ve. In equilibrium condition, pressure of O2 depends on

  1. increase mass of BaO2
  2. increase mass of BaO
  3. increase temperature on equilibrium
  4. increase mass of BaO2 and BaO both
AIPMT 2002
9

Solubility of MX2 type electrolytes is 0.5 10-4 mole/lit., then find out Ksp of electrolytes.

  1. 5 10-12
  2. 25 10-10
  3. 1 10-13
  4. 5 10-13
AIPMT 2002
10

Which has highest pH?

  1. CH3COOK
  2. Na2CO3
  3. NH4Cl
  4. NaNO3
AIPMT 2002
11

Solution of 0.1 N NH4OH and 0.1 N NH4Cl has pH 9.25. Then find out pKb of NH4OH

  1. 9.25
  2. 4.75
  3. 3.75
  4. 8.25
AIPMT 2002

All Equilibrium PYQs →

PDFDownload Equilibrium PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry