Equilibrium Questions and Answers

Which of the compounds would have the weakest conjugate base O cyclohexanone with a Ka 5 X 10 16 O cyclopentadiene with a Ka 1 X 10 15 acetylene with a K 1 X 10 25 2 chloroethanol with a K 2 X 10 14

Suppose a 250 mL flask is filled with 0 70 mol of H and 0 80 mol of HI This reaction becomes possible H g 1 g 2HI g 1 Complete the table below so that it lists the initial molarity of each compound the change in molarity of each compound due to the reaction and the equilibrium molarity of each compound after the reaction has come to equilibrium Use x to stand for the unknown change in the molarity of H You can leave out the M symbol for molarity initial change 0 X 1 0 HI 0 A X

Assertion A A Sodium hydrogen carbonate is used in fire extinguisher Reason R Sodium hydrogen carbonate is a weak base A I think the answer is b both assertion and r eason are correct and reason is not the corr ect explanation of assertion But answer given is a both are correct and r eason is correct explanation of assertion Please give your opinion and explain the an

Example 7 7 Calculate the degree of ionization of pyridine CHN in its 0 1 M solution K for pyridine is 1 5 x 10 What would be the degree of ionization of pyridine if the solution is also 0 1 M in NaOH

Find the pKa of the salicylic acid based on the pH obtained from the experiment below pH 6 15 10 ml of 0 5 w v solution of salicylic acid is used 0 5 N sodium hydroxide solution is used Results Volume of sodium hydroxide ml x Complete neutralization 0 6mL Volume of sodium hydroxide ml x 2 half neutralization 0 25 C 25 pH 6 15

d P is the ratio of the concentrations of products to the concentration of reactants present in a reaction mixture when chemical equilibrium is reached 1 point Consider the following reaction Choose the expression best describes the equilibrium constant 1 point For the reaction A 2B 2C the following concentrations were obtained for this reaction at equilibrium A 0 200 M B 0 400 M and C 3 50 M Determine the value of K for this reaction at these conditions Disregard units in your answer 1 point A reaction that yields mostly products has a K 1 point Aroaction

Calculate the degree of ionization of Example 7 7 pyridine CHN in its 0 1 M solution K for pyridine is 1 5 x 10 What would be the degree of ionization of pyridine if the solution is also 0 1 M in NaOH

A buffer solution that is 0 440 M in HNO and 0 440 M in NaNO has a pH of 3 35 Addition of which of the following would increase the capacity of the buffer for adde OH Select all that apply NaNO both HNO2 and NaNO simultaneously HNO pure water o of the ohoua

H 0 CH4 CO C H O CO CH4 C H O CO CH4 II K IV K Consider the following reaction Choose the expression best describes the equilibrium constant CO CH4 C H O Describe equilibrium constants CO CH4 C H O A I B II C III D IV

Example 7 6 Calculate the degree of ionization of 0 02 M acetic acid if its K 1 8 x 10 5 What would be the degree of ionization if the solution also contains 0 01 M sodium acetate CH COO aq H ag 100H a

55 Consider the following reactions C s O g CO g x kJ CO g O g CO g y kJ The heat of formation of CO g is 1 x y kJ mol 2 x y kJ mol 3 y x kJ mol 4 None of these

An analytical chemist is titrating 181 0 mL of a 0 7700M solution of propionic acid HC H CO with a 0 3100M solution of NaOH The pk of propionic acid is 4 89 Calculate the pH of the acid solution after the chemist has added 335 4 mL of the NaOH solution to it Note for advanced students you may assume the final volume equals the initial volume of the solution plus the volume of NaOH solution added Round your answer to 2 decimal places

5 2 points Consider a saturated solution of calcium oxalate CaC 04 CaC O4 s Ca aq C 042 aq CO C 02 H O HC O4 aq OH aq HC 04 H O H C O4 aq OH aq K p 1 3 x 108 Kb 1 8 x 10 10 Kb 1 8 x 10 13 If oxalic acid H C O4 is added to the saturated solution of CaC204 would each of the followin increase decrease or remain the same a pH b solubility of CaC 04 c K of C 04 d Ca in solution

Na2CO3 aq 2HNO3 aq 2NaNO3 aq CO2 g H2O l If it required exactly 82 53 ml of HNO3 to completely react with 25 0 mL of 0 38 M Na2CO3 Determine the concentration in Molarity M of the HNO3 solution used in the reaction This is a titration problem

3 40 J 2x10x2 Abody constrained to move in the y direction is subjected to a force F 21 15j 6k newton The work done by this force in moving the body through a distance of 10 m along y axis is S 1 100 J 17100m 2 150 J 3 120 J 4 200 self propelled vehicle of mass m whose engine delivers V v 2 mv 15 1 2 mv 3 2 4 2 A body is moved ald delivering constant pow in time t is proportiona 1 1 2 2 3 4 3 AT1 Choose the correct plo for the following poten

5 A 50 0 mL solution of 0 250 M lactic acid HC Hs0 Ka 1 4 x 104 is titrated with 0 400 M NaOH 16 What volume of NaOH solution is required to reach the equivalence point M J V2 som spont

91 If A 8 2C 0 then angle between 24 and 2c will 91 aft A 36 20 02 2 1 60 2 120 1 60 3 30 2 120 4 150 3 30 A 4 150 92 If angle making by any vector with x axis a 22 and 92 fe fut fer un with y axis R 5000 30 2 6 9 1 3 2 ANBB 20 7 13 9 PCB 1

A mixture of 100 m mol of Ca OH 2 and 2g of sodium sulphate was dissolved in water and the volume was made up to 100 mL The mass of calcium sulphate formed and the concentration of OH in resulting solution respectively are Molar mass of Ca OH 2 Na2SO4 and CaSO4 are 74 143 and 136 g mol respectively Ksp of Ca OH 2 is 5 5 x 10 6 A 13 6g 0 28 mol L 1 B 13 6g 0 14 mol L e 1 9g 0 28 mol L D 1 9g 0 14 mol L 1

For the reaction 2NO g O g 2NO g the volume is suddenly reduced to half of its value by increasing pressure on it If reaction is of first order w r t O and second order w r t NO the rate of the reaction will NCERT Pg 106 1 Decrease to 8 times of the initial value 2 Increase to 8 times of the initial value 3 Increase to 4 times of the initial value 4 Decrease to 4 times of the initial value

10 ml of a weak acid HA solution is 20 dissociated in water This solution iscompletely neutralized by 10 ml of 2x10 M NaOH solution Which of the following is are correct abou the solution log 2 0 3 A B C D pH of weak acid HA solution was 3 4 The dissociation constant of weak acid HA was 1x10 pH of solution after addition of NaOH is 7 5 Kh hydrolysis constant of the salt is1x10

Q28 NTA Test 33 Single Choice IM NH OH and IM HCl are mixed to make a total be the volume ratio of NH OH and HCI mation A 2 1 C 2 3 mathume of 300 mL If pH of the mixture is 9 26 and pK NH 9 26 then mathong mathongo B 1 2 D 3 2

ary man rain appears to be falling at his back at an angle 30 with the vertical As he starts movin forward with speed of 0 5 m s He find that the rain is falling vertically 132 14mmeren of the fa a Class XIII Spartan Batch MEC KTG 2 D Relative Motion The speed of rain with respect to the stationary man is 1 0 5 m s 2 0 53 m s 3 1 0 m s 4 0 43 m s 3 A projectile is thrown with velocity v at an angle 0 with the 133 horizontal When the projectile of the ondt ge sfera vial font a arer formareen fera fas under givit 30 six 0 5 m s far from for end wit 1 0 5 m s 2 0 53 m s 3 1 0 m s 4 0 43 m s

For the decomposition N O g N O g O g the initial pressure of N O5 is 114 mm and after 20 sec the pressure of reaction mixture becomes 133 mm The rate of reaction in terms of atm sec is 1 1 25 x 10 atm sec 3 9 5 x10 atm sec 2 2 5 x 10 atm sec 4 4 75 x10 atm sec 1

Calculate the pH and concentration of species present in a polyprotic acid solution For a 6 60 10 M solution of H S calculate both the pH and the S ion concentration H O HS K 1 0 10 7 H O S K 1 0 10 19 H S H O HS H O pH IM

163 The heat of reaction for A 0 AO is 50 kCal and AO 0 0 AO is 100 kCal The heat of reaction for A O AO is 1 50 kCal 3 100 kCal TC0182 2 50 kCal 4 150 kCal TC0184

167 The heat of solution of anhydrous CuSO and CuSO 5H O are 15 89 and 2 80 kCal mol respectively What will be the heat of hydration of anhydrous CuSO 1 18 69 kCal 3 28 96 kCal 2 18 69 Cal 4 28 96 kCal TC0189

157 Given C s O g H g O g CO g 94 2 kCal H O 68 3 kCal CH g 20 g CO g 2H O 210 8 kCal The heat of formation of methane in Kcal will be 1 45 9 2 47 8 131 20 0 4 47 3

19 For the reaction N2 g O g 2NO g the equilibrium constant is K The equilibrium constant is K for the reaction 2NO g O g 2NO2 g What is K for the reaction NO2 g 1 2N g O g AIPMT 2011 a c 1 KjK2 1 4 KjK Ciron 1 b d 105 2K K2 1 KjK2 1 2

Q27 NTA Test 32 Single Choice The solubility product of AgCl is 1 8 x 101 Precipitation of AgCl will occur only when equal volumes of which of the following solution are mixed A 10 M Ag and 10 M CI C 10 M Ag and 10 M Crathongo B 10 M Ag and 10 D 10 10 M Ag and 10 MCT mothong mathon M CT othongo

2 2H 2 19 e vakyl 4 drogen ion concentration of a 10 8 M HCI aqueous solution at 298 K Kw 10 14 is 1 1 0 x 10 6 M 2 1 0525 x 10 7 M 3 9 525 x 10 8 M 4 1 0 x 10 8 M AIIMS 2006 40 mL of 0 1 M ammoni 20 mL of Q 1 M HCI KC1 NaCl

aluation 5 An aqueous solution of 2 non volatile solute exerts a pressure o 1 004 bar at the normal boiling point of the solvent What is the molecular mass of the solute a 41 35 g mol c 23 4 g mol 7 The reactivity of the compound 1 b 10 g mol d 20 8 g mol

117 A person requires 2870 kCal of energy to lead normal daily life If heat of combustion of cane sugar is 1349 kCalmol then his daily consumption of sugar is 1 728g 342g 3 2 0 728g 4 0 342g

d none of the abo 12 Equilibrium constants K and K for the followin equilibria are related as CBSE PMT 2005 k NO g 102 g NO g O g 2NO2 g a K2 7 1 c K K NO g K 2NO g O g K2 45 1 1 K2 d K K 2 12

106 The standard heat of formation of CS will be given that the standard heat of combustion of carbon s sulphur s and CS are 393 3 293 72 and 1108 76 kJ mol respectively is 1 128 02 kJ mole 2 12 802 kJ mol 1 3 128 02 kJ mol 4 12 802 kJ mol TC0119 31 The 1 113 Giv CC hea is W

Calculate the magnitude of net work done in the following cycle for one mol of an ideal gas in Calorie Where in process BC PT constant R 2cal mol K A B 100 800 cal 200 cal 300 cal 300 T K C 900

5 The heat of combustion of ethanol determined in a bomb calorimeter is 670 48 kCal mole at 27 C What is AH at 27 C for the reaction 1 335 24 kCal 3 670 48 kCal 2 671 08 kCal 4 670 48 kCal E max 1 C 2 C 3 C

3 For the reaction CO g O g CO g Which one of these statement is correct at constant T and P 1 AH AE 2 AH AE 3 AH AE 4 AH is Independent of physical state of reactants

10 For the water gas reaction C s H O g 1 CO g H g The standard Gibb s energy of reaction at 1000 K is 8 1 KJ mol Value of equilibrium constant is 1 2 6 2 6 2 3 8 2 4 10 dissolution

Consider the following equilibrium reactions X Y K 2 Y Z K 0 2 Equilibrium constant for the reaction X Z is 0 4 0 1 2 2 hr

n 40J heat is energy of the TH0020 26 A mixture of 2 moles of carbon monoxide and one mole of oxygen in a closed vessel is ignited to get carbon dioxide If AH is the enthalpy change and AE is the change in internal energy then 1 AH S AE 2 AH AE 3 AH AE 4 Not definite

For the following reaction AB 10 kcal OH ve increase in temperature 1 increases rate of the forward as well as backward reaction 2 increases rate of the forward reaction but decreases that of backward reaction decreases rate of the forward reaction but increases that of the backward reaction 4 decreases rate of forward as well as backward reaction

Calculate the number of moles of AgI which is dissolved in 1 0 L of 1 0 M AgCN solution Ksp for AgI and Kc for Ag CN are 1 2 x 10 7 M and 7 1 x 101 M2 respectively A 4 9 B 0 49 C 0 049

For which of the following gaseous equilibria at a constant temperature doubling the volume would cause a shift of equilibrium to the right A B C 2C0 0 2C02 N 3H 2NH3 N 0 2NO

4 5 x x 10 mol L CK0003 Which of the following statement is correct for a reaction X 2Y Product p 1 The rate of disappearance of X twice the rate of disappearance of Y 2 The rate of disappearance of X 1 rate of appearance of product p 3 The rate of appearance of product p the rate of disappearance of Y 4 The rate of appearance of product p rate of disappearance of X nu the

CK0012 13 Which of the following rate law has an overall order of 0 5 for reaction involving substances x y and z 1 Rate K C C C 2 Rate 3 Rate 4 Rate K C c c K C C C K CMC C

For a general chemical change 2A 3B products the rate of disappearance of A is r and of B is The rates r and r are related as 2 5 1 3r 2r 3 2r 3r 4 r T 2r 2

1 In each of the following total pressure setup at equilibrium is assumed to be equal and is I atm with equilibrium constant K given 1 CaCO3 s CaO s CO g K INH HS s NH g H S g K II NH CO NH 2NH g CO 9 K In increasing order 1 K K K 3 K K K 2 K K K 4 None of these

8 The equilibrium constants for the reaction H BO glycerine H BO glycerine is 0 90 Glycerine present per litre of 0 1 M H BO to convert 60 of H BO into H BO glycerine is 1 0 167 M 2 1 67 M 4 10 67 M 3 0 0167

1 In the reaction AB C initially 3 moles of A were taken At equilibrium 0 75 moles of B are formed The degree of dissociation of Ais 1 0 75 2 0 25 310 50 4 0 40

CK0002 In a catalytic reaction involving the formation of ammonia by Haber s process N 3H 2NH the rate of appearance of NH was measured as 2 5 x 10 mole L s The rate of disappearance of H will be 1 2 5 x 10 mol L s 2 1 25 x 10 mol L s 3 3 75 x 10 mol L s 4 5 x 10 mol L s CKO007