Equilibrium Questions and Answers

4 Cannot predict The pH of a mixture of 100 mL of 0 5 M HC1 47 and 100 mL of 0 6 M NaOH solution is 1 11 3 2 10 3 3 12 7 4 4 3 4 100 ff 0 5 M HCI 100 Ft 0 6 M NaOH facfm pH 1 11 3 2 10 3 3 12 7 4 4 3

The activation energy for a reaction at the temperature T K was found to be 2 303 RT J mol 1 The ratio of the rate constant to Arrhenius factor is Karnataka CET 2010 A B C 2x10 3 10 1 10 2 C 10 2

the temperature is raised from 300 K to 310 K is log 2 0 3 OPTIONS CLEAR SELECTION MARK FOR REVIEW A 50 6 kJ mol 1 OB 75 45 kJ mol 1 C OC 45 5 kJ mol 1 DI Eo ALLmal 1

For the reaction N 05 9 2NO g O g the value of rate of disappearance of N O5 is given as 6 25 x 10 3 mol L 1 s 1 The rate of formation of NO2 and O2 is given respectively as CBSE AIPMT 2010 A B C D 6 25 x 10 3 mol L s and 3 125 x 10 3 mol L 1 s 1 6 25 x 10 3 mol L 1 s and 6 25 x 10 3 mol L 1 s 1 6 25 x 10 3 mol L s and 1 6 25 x 10 3 mol L 1 s1 1 25 x 10 2 mol L 1 s and 3 125 x 10 3 mol L 1 s 1

pH of a Buffered Solution Using tabulated Ka and Kb values calculate the pH of a solution made by mixing 105 00 mL of 0 900 M HOCI with 65 00 mL of 0 650 M NaOH The answer is 7 36 please help explain how to get the answer Thanks

Consider how best to prepare one liter of a buffer solution with pli 3 66 using one of the weak acid conjugate base systems shown here Weak Acid Conjugate Base K pk HC 0 C 0 6 4 x 105 4 19 H PO HPO HCO co 6 2 x 10 4 8 x 10 11 7 21 10 32 How many grams of the potassium salt of the weak acid must be combined with how many grams of the potassium salt of its conjugate base to produce 1 00 L of a buffer that is 1 00 M in the weak base grams potassium salt of weak acid

Which is are correct statements about following equilibrium N O4 g 2NO g Degree of dissociation of N O4 g increases when temperature increases O Vapour density of gaseous mixture decreases when temperature increases O Partial pressure of NO decreases when Helium gas added under constant pressure Partial pressure of N O4 increases when Helium gas added under constant volume

If Cl and PCI can react to form PCI according to following reaction Cl PC1 PCI In tube A 355 gm Cl is taken and in tube B 1375 gm PCI is taken When half the mass of gas in tu A is transferred to B reaction look place in B After the reaction is complete half of the mass mixture in B is again transferred to A to cause same reaction in container A no reversibility Select the correct option s A Tube A contains 3 75 moles of PCI 1 25 moles of PCI finally B Tube A contains 2 5 moles of Cl 1 25 moles of PCI finally C Tube B contains 3 75 moles of PCI 1 25 moles of PCI finally D None of these 3

A 23 18 mL solution containing 1 769 g Mg NO is mixed with a 34 58 mL solution containing 1 432 g NaOH Calculate the concentrations of the ions remaining in solution after the reaction is complete Assume volumes are additive If a species fully precipitates type 0 Be sure your answer has the correct number of significant digits MM MNO M Na M OH 0

On titration of 5 ml 0 8 M sodium carbonate solution with 0 4N HCI 3 Column I Column II Volume of HCI added in ml A 0 B 5 C 10 D 15 For H CO3 K 10 7 K 10 P Buffer solution of HCO3 and CO Q pH 7 R pH 9 S pH 7 T OH H

Part B Using K 2 NO g N2 g O2 g 7 Initially NO 0 772 M If K 30 25 what is NO eq 8 Initially N 0 10 M and 0 0 10 M If K 0 040 find NO eq 9 NO 0 50 M and N2 i 0 030 M If K 7000 find NO eq 10 Initially NO 0 51 N 0 42 and 0 0 19 If K 0 115 what is NO eq hint calculate Q to determine which direction the reaction will proceed

Consider how to prepare a buffer solution with pH 3 47 using one of the weak acid conjugate base systems shown here by combining 1 00 L of a 0 304 M solation of weak acid with 0 363 M sodium hydroxide Weak Acid HNO HCIO HCN Conjugate Base NO CIO CON K 4 5 x 104 3 5x108 4 0x 10 10 pk 3 35 7 46 9 40 How many L of the sodium hydroxide solution would have to be added to the acid solution of your choice

1L Mixture of 0 1M CH COOH 0 01M CH COO correct log 5 0 7 log 7 0 9 pH of the given solution is 4 Ca pH of the given solution is 3 7 is taken If K CH COOH 2x10 5 a which of the following statements are There is an increase in pH by 0 9 when 0 05 moles of NaOH is added to the 1L of the given solution There is an increase in pH by 0 3 when 0 05 moles of NaOH is added to 11 of the given solution

Pure water is saturated with pure solid AgCl A silver rod is placed in the solution and the potential is measured against normal calomel electrode at 25 C This experiment is then repeated with a saturated solution of Agl If the difference in potential in the two cases is 0 177 V the ratio of solubility product Kp of AgCl and Agl at the temperature of the experiment is 10 Determine the value of x 6 Ag AgCl s Calomel Saturated solution Ag Ag1 s Calomel Saturated solution Eagl M E E EAgCl Ag This can be understood as Ag Agi s AgCl s Ag Or Ag Ag aq Ag aq Ag K AgI K AgCl 0 0 177 0 059 log 1 K AgCl sp K Agl 0 177 10 Ag Ag E

64 Calculate the carbonate ion concentration CO 2 in a 0 10 M solution of the weak acid carbonic acid H CO3 The dissociation constants of carbonic acid Ka 4 5 x 10 7 and Kaz 4 7 x 10 1 1 4 7 x 10 M 2 1 0 10 M 3 4 5 107 M 4 2 1 x 10 are

4 Consider the irreversible reaction for the conversion of chlorophenol C6H4OHCl or CP to dioxin C6H3C1O2 2 C6H4OHCl 2 02 aq C6H3CIO2 2 H O TCP k CP 2 O aq 5 a If k 10 L 5 mol 5 sec how long would be required to form 109 M dioxin in a batch reactor with an initial solution containing 107 M chlorophenol and a constant O aq of 2 5 x 104 M b Provide the structure for chlorophenol and dioxin explain their sources in the environment and comment on their relative toxicity

Which of the following is are not a buffer solution 500 mL of 0 1 N CH COOH 500 mL of 0 1 N NaOH 500 mL of 0 1N CH COOH 500 mL of 0 1 N HCI 500 mL of 0 1 N CH COOH 500 mL of 0 2N NaOH 500 mL of 0 2 N CH COOH 500 mL of 0 1N NaOH

Solubility product Ksp of CaCO3 at 25 C is 10 10 What would be the concentration of H CO3 is required to precipitate CaCO3 from solution of 10 3 M Ca 2 ions 10 7 10 9 10 6 10 13 Marks 4 1

Which of the following combinations of chemicals makes a buffer Mark all that apply Identifying solutions as buffers on a quiz or exam is a critical skill For this chapter many problems ask you to find the pH of a solution The challenge is classifying the solution appropriately and then selecting the right approach to finding its pH roughly equimolar mixture of acetic acid and sodium acetate solution that is 0 1 M each in hydrochloric acid and sodium chloride solution made by combining 25 mL of 0 1 M acetic acid with 12 5 mL of 0 1 M sodium hydroxide solution that is 0 1 M each in ammonia and ammonium chloride

If Ka Ka Ka values for H PO4 are 103 108 and 10 2 respectively then what is the pH of an aqueous solution containing equimolar mixture of Na HPO4 and Na3PO4 Your answer

At 100 K temperature A g is 50 dissociated into B g and C g as per the reaction A g B g C g at 1 atm pressure The Gibbs energy change at t temperature is Options 100 RIn3 100 RIn3 330 3 Rin

Which of the following statement is true hr m O A catalyst alter Gibbs energy of a reaction O The action of the catalyst cannot be explained by intermediate complex theory O A catalyst does not change the equilibrium constant of a reaction O Catalyst catalyses the non spontaneous reaction

Which of the following mixtures can NOT act as a buffer 0 HCl CH3COONa 2 1 molar ratio respectively CH3COOH NaOH 2 1 molar ratio respectively CH COOH NaOH 1 2 molar ratio respectively CH COOH NaOH 1 1 molar ratio respectively

2A g BCJ approach of equilibrium concentrations of A B and I are 0 5 M 3M and 1 5M respectively At the start of the reaction I was absent but I was present cinitial concentration of PE 0 5 M Identify the correct statement 4 the concentration of D at equilibrium is 4 5 M 6 R 450 M 0 25 2 Al Kc S A B CD CD

0 ml of 2M CaCl solution is mixed with 60 ml of AICI3 solution and the mixture is diluted to 500 ml If the diluted solution contains 0 7 moles chloride ions the molarity in mol litre of AlCl3 solution usec

Consider the following sparingly soluble salts having same solubility product in their saturated solution in water a XY b X Y C XY3 The correct order of increasing solubility of these salts in water will be A A B C B C B A C B A C D B C A Your Answer B Correct Answer Description

Why they say kp is independent of pressure It is directly proportional to total pressure is not it correct OVO TH 55 The equilibrium constant k for the reaction A 2B is related to degree of dissociation of A is a and total pressure P is 1 kp 2 kp P 3 kp 05 pressure 4 Kp P 4a P 1 2 kp is independent of pressure 2a P 1 pressure 4a P 1 2 1 kp is directly proportional to kp is directly proportional to P kp is directly proportional to

We were taught in class that in this case rxn goes to side vith less moles l e forward so why is it not working here ols don t send previous answers give a nicer detailed expla nation At some constant equilibrium temperature T K following gaseous equilibrium is set in a vessel fitted with a movable piston N 3H 2NH Now at this equilibrium state total pressure is increased and allowed to attain a new equilibrium state Which of the following will be true at the new equilibrium state Concentration of NH3 will increase but that of N and H will remain same Concentration of NH3 N and H will increase There shall be no change in the concentration of any of these gases Concentration of NH3 will increase but that of N and H will decrease

entre of Excellence Consider the decomposition of solid NH4HS in a flask containing NH3 g at a pressure of 2 atm What will be the partial pressure of NH3 g and H S g after the equilibrium has been attained Kp for the reaction is 3 A PNH3 C PNH3 4 atm PH S 2 atm 3 atm PH S 1 atm 1 732 atm PH S B PNH3 D PNH3 1 atm PH S 1 732 atm 1 atm

Example 24 The solubility product of Ag C 0 at 25 C 0 1520 mole in 500 mL of water is shaken with excess of 1 29 x 10 mol L A solution of K C O4 containing Ag CO till the following equilibrium is reached Ag CO3 K C O Ag C O K CO At equilibrium the solution contains 0 0358 mole of K CO Assuming the degree of dissociation of K C O4 and K CO3 to be equal calculate the solubility product of Ag CO i e JIT

Compound A decomposes according to the equation A g 2 B g C g A sealed 1 00 L container initially contains 1 84 10 3 mol of A g 1 28 10 3 mol of B g a 5 51 104 mol of C g at 100 C At equilibrium A is 2 10 10 3 M Find B and C Solve for the equilibrium concentrations of B and C Bleq x 10 M

2 For the reaction taking places at certain temperature NH COONH s 2NH g CO g If equilibrium pressure is 3X bar then AG would be A RTln9 3RTX C 3 RTlnX B RTln4 3RTlnX D RTln4 3RTlnX

Two solids A and B equilibria in a vessel A s X g 2Y g shows the following Kp 9x10 Kp2 B s Z g 2Y g What will be the total pressure over a mixture of A and B in atm A 0 45 C 0 35 B 0 60 D 0 75 4 5 10

5 in PP3 P has a lone pair of electrons 3 dic isame Kse values of 6 2 x 10 13 at room temperature Which NEET 2016 MY and NY3 two nearly insoluble salts have the statement would be true in regard to MY and Nyns of 1 The addition of the salt of KY to solution of MY and NY will have no effect on their solubilities 2 The molar solubilities of MY and NY3 in water are identical 3 The molar solubility of MY in water is less than that of NY 4 The salts MY and NY are more soluble in 0 5 M KY than in pure water 3 Sol Answer 3

Assignment Set 2 49 H S gas when passed through a solution of cations containing HCI precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group It is because AIPMT Prelims 2005 1 Presence of HCI decreases the sulphide ion concentration 2 Presence of HCI increases the sulphide ion concentration 3 Solubility product of group Il sulphides is more than that of group IV sulphides 4 Sulphides of group IV cations are unstable in HCI ol Answor 1

208 Equilibrium Solution of Assignment Set 2 11 The Ksp of Ag CrO4 AgCl AgBr and Agl are respectively 1 1 x 10 12 1 8 x 10 10 5 0 10 13 8 3 10 17 Which one of the following salts will precipitate last if AgNO3 solution is added to the solution containing equal moles of NaCl NaBr Nal and Na CrO4 AIPMT 2015 1 Ag CrO 3 AgCl Sol Answer 1 2 4 Agl AgBr

hic gas is higher than that of a monoatomic gas Heat Ca Multiple Choice Questions with ONE correct answer 1 The standard state Gibbs free energies of formation of C graphite and C diamond at T 298 K are 1985 A G C graphite 0 kJmol A G C diamond 2 9 kJmol The standard state means that the pressure should be 1 bar and substance should be pure at a given temperature The conversion of graphite C graphite to diamond C diamond reduces its volume by 2 x 10 6 m mol If C graphite is converted to C diamond isothermally at T 298 K the pressure at which C graphite is in equilibrium with C diamond is Useful information 1 J 1 kg m s 2 1 Pa 1 kg m s 2 1 bar 105 Pa A 14501 bar C 1450 bar B 58001 bar D 29001 bar 2017

6 Consider the following liquid vapour equilibrium Liquid Vapour Which of the following relations is correct 3 dinP AH dT RT2 dinP AH Sol Answer 1 RT 2 4 dinG AH dT RT dinP dT AH T Equilibrium 201 NEET 2016

2 Decreased 3 Remains constant 4 May increased or decreased depends on exothermic or endothermic nature What will be the equilibrium constant at 127 C If equilibrium constant at 27 C is 4 for reactic N 3H 2NH AH 1 4 x 10 46 06 kJ 2 2 x 10 3 3 10 4 4 10

8 for the reaction at 500K 2A g B g C g AH 300 Kcal mol4moles of A and 3 moles of B are taken Value of heat change at constant volume on completion of reaction will be 1 299 Kcal mol 3 598 Kcal mol 2 596 Kcal mol 4 301 Kcal mol

What is an example of useful work 1 Electricity generation from solar cells used to power electric motors 2 Expansion of a vessel due to creation of gas in a chemical reaction 3 Contraction consumption 4 A system at equilibrium of a vessel due to gas in a chemical reaction

1 lit solution of Na3PO4 Na2HPO4 1 lit solution of Na3PO4 Na2HPO4 1 M each 1 M each Only water is electrolysed in both compartments 2 moles of electrons are transfer from anode to cathode pKaj pKa2 pKa3 values of H3PO4 are 4 6 8 respectivel Find pH of anode

130 K for HCN is 5 x 100 at 25 C For maintaining a constant pH 9 the volume of 5 M KCN solution required to be added to 10 mL of 2 M HCN solution is a 4 mL b 2 5 mL c 2 mL d 6 4 mL AUMS

33 The pH of a solution obtained by mixing 100 ml of 0 2 M CH3COOH with 100 ml of 0 2 M NaOH will be PK for CH COOH 4 74 and log 2 0 301 1 4 74 3 9 10 2 8 87 4 8 57

3 For the reaction A 3B 2C D initial mole of A is twice that of B If at equilibrium moles of B and are equal then percent of B reacted is 1 10 3 40 Refern des ga 2 20 4 60 4 uilibrium A g 4B g AB g is attained by mixing equal moles of A and B in a one litre vessel

If you dissolved the salt methylammmonium cyanide CH3NH3 CN in water what type of solution would you expect to have K HCN 4 9 x 10 10 Kb CH3NH 4 4 x 10 4 Neutral Can not be determined from the information given Basic Acidic

3B The distribution coefficient of Caffeine in the methylene dichloride water solvent system is 4 6 a In which solvent is caffeine more soluble Ans b Caffeine in the amount of 2 mg is dissolved in 100 mL of water Following the same procedure as that for benzoic acid 100 mL of methylene dichloride is used instead of 600 L how many

59 The solubility of a salt A B in pure water will be Ksp of A B 1 08 10 6 1 3 x 10 6 mol L 1 3 4 10 2 mol L 1 60 The oxidation state of Cr in CrO is 2 2 x 10 8 mol L 1 4 3 x 10 18 mol L 1

2 For the reaction N 3H 2NH3 the rate of change of concentration for hydrogen is 0 3x10 Ms 1 The rate of change of concentration of ammonia is 1 0 2 104 2 0 2 x 10 4 3 0 1 10 4 4 0 3 x 10 4

2X g Y g Z g The equilibrium concentration of X g Y g and Z g are respectively 4 2 and 2 M How man moles of X g is to be added so that the concentration of Y g becomes 3M at the new equilibrium