Equilibrium Questions and Answers

39 Which of the following factors will favour the backward reaction Cl g 3F g 2CIF g AH ve Addition of inert gas at constant pressure Increase in temperature B Addition of Cl gas Increasing the volume of the containe

Which one of the following options is correct if the activation energies of two reactions are Ea and Ea2 with Ea Ea2 and if the temperature of the reacting systems is increased from T to T A B kl K k K k K 24 24 K2

13 Aqueous solutions of HNO KOH CH COOH and CH COONa of identical concentrations are provided The pair s of solutions which form a buffer upon mixing is are A HNO and CH COOHMA B KOH and CH COONa OHNO and CHCOONa CH COOH and CH COONa 3

A solid XY kept in an evacuated sealed container undergoes decomposition to form a mixture of gases X and Y at temperature T The equilibrium pressure is 10 bar in this vessel Kp for this reaction is A B 5 10 25

C 0 25 Two liquids of equal masses one at 20 C and the other at 40 C are mixed together The temperature of the mixture is 32 C The ratio of their specific heats is A 3 2 C 1 3 B 1 1 D 2 3 11 constant

Determine which solution in each pair is more acidic A 0 0100 M in HCl and 0 0100 M in KOH B 0 0100 M in HF and 0 0100 M in KBr C 0 0100 M in NH Cl and 0 0100 M in CH NH Br D 0 100 M in NaCN and 0 100 M in CaCl

2 A solution contains 1 29 10 2 M calcium acetate and 1 12 10 2 M barium nitrate Solid potassium chromate is added slowly to this mixture What is the concentration of barium ion when calcium ion begins to precipitate Ba2 M

You have available 1 liter of a buffer solution containing 0 100 M fluoride ions F and 0 126 M hydrogen fluoride HF What is the pH of the buffer The Ka value for HF 6 8 x 10 4 Do not enter a unit with your answer Round your answer to three places to the right of the decimal point What is the pH of the buffer in question 1 after the addition of 0 010 moles of sodium hydroxide NaOH You may assume the solution volume does not change after the addition of NaOH Do not enter a unit with your answer Round your answer to three places to the right of the decimal point

Q 20 Which mixture of solutions having pH 7 Given H CO3 K1 4 2 x 10 7 K 4 8 10 11 H3PO4 K1 7 5 x 10 3 K 6 2 x 10 8 K3 1 0 10 12 Answer A B C Your Attempt Correct answer 40 ml of 0 050 M Na2CO3 50 ml of 0 040 M HCI 40 ml of 0 020 M Na3PO4 40 ml of 0 040 M HCI 50 ml of 0 10 M Na3PO4 50 ml 0 10 M NaH2PO4 O D 40 ml of 0 10 M H3PO4 40 ml of 0 10 M Na3PO4

war the equilibrium AB g A g B g K is equal to four times the total pressure The number of moles of A formed is x3 S Mi 1 12 2 3 5 9 P xx 7 el 4KP 2 2 p 4pp kef 2 AJB A JAB 4 5

ZnS is not precipitated by passing H S in acidic medium 3 4 14 but CuS is precipitated The reason for it is 4 4 14 1 Ksp CuS Ksp ZnS 2 Ksp CuS Ksp ZnS 3 Ksp CuS Ksp ZnS 4 none of these 27 When ec which c Kp of

AB is a strong electrolyte and AC a weak electrolyte Both are dissolved in water separately and their solutions are mixed together Question Type Single Correct Type 1 The degree of ionisation of AC will decrease 2 The degree of ionisation of AB will decrease 3 AB will be precipitated 4 AC will be precipitated

When H S is passed through an aqueous solution of an equimolar mixture of Zn and Pb acidified with dilute acetic acid ZnS is not precipitated because 1 Ksp ZnS Ksp PbS 2 Kap ZnS Ksp PbS 3 H S decreases the Ksp of Zns 4 H S increases the Kp of PbS Fill OMR Sheet If above link doesn t work please go to test link from where you got the pdf and fill OMR from there

25 There sparingly soluble saltrs A X AX and AX3 have the same solubility product Their solubilities will be in the order 1 AX AX A X 2 AX3 A X AX 3 AX AX3 A X

In the beginning of the reaction A B C 2 moles of A are taken out of which 0 5 mole gets dissociated What is the amount of dissociation of A 1 0 5 2 1 3 0 25 4 4 2

BOX 3 The equilibrium constant K for the reaction 2HCl g H g Cl g is 4 x 10 34 at 25 C What is the equilibrium constant for the reaction 1 2 x 10 17 H g Cl g HCl g 2 2 2 2 5 x 1033 3 5 x 106 4 None of these

All Physics View in Question No 13 At 100 K temperature Az g is 50 dissociated into B g and C g as per the reaction A2 g B g C g at 1 atm pressure The Gibbs energy change at this temperature is 0 100 Rin3 O 100 Rin3 O 230 3 Rin3 O230 3 Rin3

D CH NH 0 1 mole K 5 x 10 4 is added to 0 08 moles of HCl and the solution is diluted to one litre The resulting hydrogen ion concentration is 1 1 6 x 10 11 3 5 x 10 5 2 8 x 10 11 4 8 10

What will be he pressure of the gase mixture at equilibrium if AB is 20 dissoci according to the following react AB g A g 2B g Kp represents equilibrium constant of the reaction

1 g 2XO g X g 20 g K K K 1 x 1024 K 2 5 x 1010 So the stability of XO XO BEGINNER S BOX 2 In which of the following reaction product is more stable 1 N 3H 2NH K 2 3 10 2 N O 2NO K 2 10 x 3 H 1 2HI K 294 4 XeO O F XeO F K 1 4 10 F2 2 KA

A reaction in equilibrium in a 1 00L container is found to contain 0 025 moles of A 0 097 moles of B and 0 118 moles of C A B C Calculate the value of Kc for the reaction If 0 067 moles of A and 0 082 moles of B are added to the reaction how many moles of C will be present at equilibrium

base indicator has Kin The acid form of the indicator is red and the 3 0 x 10 5 basic form is blue The change in H required to change the indicator from 75 red to 75 blue is 1 8 x 10 5 M 3 3 10 5 M 2 9 x 10 5 M 4 3 x 104 M 195 W C

5 00 mL of 0 10 M oxalic acid solution taken in a conical flask is titrated against NaOH froma burette using phenolphthalein indicator The volume of NaOH required for the appearance of permanent faint pink color is tabulated below for five experiments What is the concentration in molarity of the NaOH solution Exp No 1 2 3 4 5 Vol of NaOH mL 12 5 10 5 9 0 9 0 9 0

15 Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are 382 64 kJ mol and 145 6 kJ mol respectively Standard Gibbs energy change for the same reaction at 298 K is a 221 1 kJ mol b 339 3 kJ mol c 439 3 kJ mol d 523 2 kJ mol

Use Hess s law to calculate AG rxnusing the following information NO g O g NO2 g AG rxn 2 03 g 3 O2 g 02 g 2 0 g NO g O3 g NO2 g O2 g AG rxn 489 6 kJ AG rxn 463 4 kJ AG rxn 199 5 kJ

Solubility of AgCl in 0 1 M aqueous NaCl solution is Ksp fo AgCl 1 2 x 10 101 1 x 10 5 M 1 2 10 M 1 2 x 10 5 M 10 M

4 Consider the equilibrium system involving the oxidation of sulfur dioxide 2SO2 g 102 g 2SO3 g AH 192 kJ Sketch on the graph below with the given equilibrium concentrations the effect of a an increase in SO2 at t 1T b the addition of neon inert gas at t2 1T c a decrease in temperature at t3 1T CONC SO 0 SO TIME

A mixture of 9 22 moles of A 10 11 moles of B and 27 83 moles of C is placed in one liter container at a certain temperature The reaction is allowed to reach equilibrium At equilibrium the number of moles of B is 18 32 Calculate the equilibrium constant for the reaction A g 2B g 3C g

7 The solubility product of a salt having general formula MX2 in water is 4 x 10 12 The concentration of M ions in the aqueous solution of the salt is 2005 a 4 0 10 10 M b 1 6 10 4 M e 1 0 10 4 M d 2 0 10 6 M

4 At equilibrium a 0 100 M solution of Acetic Acid contains the following concentrations HC2H3O2 aq H aq C2H302 aq 0 0990 M 1 33x10 3 M 1 33x10 3 M Please calculate the equilibrium constant Keq

2 a b c The acid dissociation constants for sulfurous acid are Kat 1 2 x 10 and K 6 6 x 10 Calculate the pH of a solution of 0 10 M H SO Calculate the pH of a solution of 0 10 M Na SO Calculate the pH of the solution resulting when equal volumes of the soluti

What is the maximum concentration of equimolar solutions of FeSO4 and Na S so that when mixed in equal volumes there is no precipitation of FeS Ksp of FeS 6 25 x 10 18 1 2 5 x 10 M 3 5 x 10 18 M 2 5 x 10 8 M 4 5 x 10 9 M

It is impossible for a reaction to take place 1 AH is ve and AS is ve 2 AH is ve and AS is ve 3 AH is ve and AS is ve 4 AH is ve and AS is ve

Identify which of the following mixtures of conjugate base A weak acid HA OH and H that cannot be used to prepare a buffer to stabilize pH There may be more than one correct answer A A and H B HA and H C A and OH D HA and OH E HA and A

8 Consider the following reaction at equilibrium in a closed container CaCO CaO CO2 g hich of the following statements is true if the volume of the container is increased A The concentration of CaCO3 would increase B The concentration of CaCO3 would decrease C The amount of CO would increase D The amount of CO would decrease

What is chemistry spontaneity How is AG related to spontanei Make up a reaction process that is i Always spontaneous ii Never spontaneous iii Spontaneous higher than a temperature iv Spontaneous lower than a temperature Examples A solid melts into a liquid and is exothermic 2 H O 1 H g O g AH 35 kJ

A 5 3 x 10 10 M B 5 3 x 10 8 M 10 D 5 3 x 10 11 M 4 Let the solubilities of AgCl in pure water 0 01 M CaCl2 0 01 M NaCl 0 05 M AgNO3 be S1 S2 S3 S4 respectively What is the correct order of these quantities Neglect any complexation A S1 S4 S3 S2 B S1 S2 S3 S4 C S1 S3 S2 S4 D S4 S2 S3 S1 fo NO will be represented by which concentration term Assur 5 3 10 7 M x

At 25 C the enthalpy change for the ionization of trichloroacetic acid is 6 3kJ mol and the entropy change is 0 0084 kJmol K Then pKa of trichloro acetic acid is 1 1 74 3 0 66 2 2 52 4 4 72

3 3 33 10 9 4 3 33 10 10 23 To a 200 ml of 0 1 M weak acid HA solution 90 ml of 0 1 M 23 solution of NaOH be added Now what volume of 0 1 M NaOH be added into above solution so that pH of resulting solution be 5 K HA 105 1 2 ml 2 20 ml 3 10 ml 4 15 ml 3 3 33 x 10 9 4 3 33 10 10 HA 0 1M 200 ml NaOH 90 ml faca fara M 1 fan 0 1 M Nafa facra ap afruit facer a pH 5 K HA 10 1 2 ml 2 20 ml 3 10 ml 4 15 ml

3 39 An equilibrium system for the reaction between hydrogen and iodine to give hydrogen iodide at 765K in a 5 litre volume contains 0 4 mole of hydrogen 0 4 mole of iodine and 2 4 moles of hydrogen iodide The equilibrium constant for the reaction is H 1 2HI is 2 15 0 1 march 1 36 0

A 2B C K 1 987x10 8 mole2litre 2 then at equilibrium the reaction mixture contains greater number of moles of 1 A 2 B 3 C 6 4 Equal moles of A and B

The value of AH for the reaction X g 4Y g 2XY4 9 is less than zero Formation of XY g will be favoured at AIPMT Prelims 20117 1 High pressure and low temperature 2 High tremperature and high pressure 3 Low pressure and low temperature 1 4 High temperature and low pressure

32 Which is the strongest acid pK value is given HCOOH 3 771 a 2 c CH3COOH 4 7 33 Given Enthalpy of ionization of two acids b C6H5COOH 4 22 ROOD d CH3CH COOH 4 88

43 How much water must be added to 300 mL of 0 2 M solution of CH3COOH K 1 8 10 5 for the D O D a of the acid to double b 900 mL a 600 mL 1200 mL d 1500 mL 44 What is NH in a solution that contain 0 02 M NH 3 K 1 8 10 5 and 0 01 M KOH

5 If the value of an equilibrium constant for a particular reaction is 1 6 x 1012 then at equilibrium AIPMT 2015 the system will contain 1 Similar amounts of reactants and products 2 All reactants 3 Mostly reactants 4 Mostly products bo extil OS

Molar solubility of Ni OH in 0 5 M Ca OH is Ksp of Ni OH 2 10 M Options 13 2 10 M 14 2 10 M 2x107 M 16 2 x 10 M 15 Solution Answer 3 NCERT Reference Equilibrium XI part 1 Page No 230

If initially 3M each of CO and H O are present and equilibrium constant Kc 4 the equilibrium concentration of CO gas for the reaction CO g H O g CO g H g is Options 1 M 2 M 3 M 4 M Solution Answer 2

Which of the following combinations will make a buffer solutions i CH COONa 2 mol HCl 1 mol iii CH COOH 1 mol CH COONa 1 mol 1 i 2 H ii CH COOH 2 mol NaOH 1 mol 3 0 0 4 i ii

2 In a mixture of 0 1 M AgNO3 and 0 1 M Pb NO3 2 solution 0 1 M KCl solution is added dropwise to precipitate AgCl When precipitation of PbCl just starts what is the concentration of Ag in the solution Given solubility product LAgCI 1 5 10 0 LPbc12 2 4 10

Aniline behaves as a weak base When 0 1 M 50 mL solution sample of aniline was mixed with 0 2 M 12 5 mL solution of HCl the pH of resulting solution was 8 Then the correct information is are log 5 0 7 log3 0 48 A pH of 0 01 M solution of anilinium chloride is 5 B pH of original solution of aniline is 3 5 C Upon adding the same aniline sample 50ml 0 1M to the above mixture pH of resulting solution becomes 8 48 D Upon adding the same HCl sample 12 5ml 0 2M to the above mixture pH of resulting solution becomes 4 59