Equilibrium Questions and Answers

200 mL of 0 1 M aqueous solution of acetic acid is mixed with equal volume of equimolar HCI solution at 27 C If 1 g of NaOH is added to this then the H in final solution is x x 10 Y M represented in scientific notation Find x y Ka of acetic acid 2 10 5

An ionic compound has the formula AB and an aqueous molar solubility of 7 90X10 Calculate the AG in kJ mole for this process at a temperature of 22 84 C Round your final answer to two decimal places

Ascertain which indicator is best to use in order to assess equivalence point and explain your reasoning Indicators Indicator Methyl Orange Methyl Red Phenol Red Thymol Blue pka 3 46 5 00 7 81 8 90

0 1 a compound AB g dissociates according to the reaction 2AB g 2AB g B g with a degree of dissociation which is small as compared to unity The expression for K in terms of x and total pressure P is 2 Px 2 Px 3 p 2px 2px p px 4 0 07 3 2 pr 2pm pu exp x to

na closed system A s 2B g 3C g if the partial pressure of C is doubled then partial pressure c 3 will be 1 Twice the orignal pressure 2 Half of its orignal pressure 4 2 2 times its original pressure 1 times the original pressure 2 2 Sulphide ion reacts with solid sulphur 3 K 10

Ammonium sulphide and ammonium selenide on heating dissociates as 4 2S S 2NH3 g H S g K thongo 9 10 atm mat NH4 2Se s 2NH3 g H Se g Kp2 4 5 ong The total pressu A 0 15 atm C 0 45 atm over the solid mixture at equilibrium is hongo Ature anotho lov mathongo mathongo mathongs B 0 3 D 0 6 atm

Sulphide ion reacts with solid sulphur S2 aq S s S2 aq K 10 S2 aq 2S s S3 aq K 130 The equilibrium constant for the formation of S 2 aq from S 2 aq and sulphur is 1 10 2 13 3 130 4 1300

J mol eats of reactions 3 kCal mol 837 2 kCal mol 363 7 kCal mol than 13 7 kCal 1 13 3 Less than 13 7 kCal 4 Cannot be predicted If H OH H O 13 7 kCal then heat of complete neutralisation of one gram mole of H SO with strong base will be 2 27 4 Kcal 1 13 7 Kcal 4 3 425 KCal 3 6 85 Kcal 143 Heat of neutralisation of a strong dibasic acid reaction AZ OHC X 142 wory cyclo 1 121 kJ mol 3 242 kJ mol BOND ENERGY RESO 161 Bond energy of a molec 1 Is always negative 2 is always positive her positive or ne

A glass electrode dipped in a soln of pH 5 gave an em of 0 25 V with Hg Hg Cl KCl 0 1 M at 298 K Whe dipped in a solution X of unknown pH at the sam temperature the recorded emf was 0 15 V What is the pH of X Electrode potential of calomel electrode a standard conditions is 0 2810 V Do you think that th

1 Heat of dissociation of benzene to elements is 5535 kJ mol The bond enthalpies of C C C C and C H are 347 3 615 0 and 416 2 kJ respectively Magnitude resonance energy of benzene is 1 151 kJ 2 15 1 kJ 3 151 kJ 4 1511 kJ 245

The molar solubility in mol L of a sparingly soluble salt MX is s The corresponding solubility product is Kp s is given in terms of Ksp by the relation 1 5 1 6 2 s 128Kp 1 s K 256 3 S HCI 128 1 5 4 s 256K

A mixture of NH3 g and N H4 g is placed in a sealed container at 300K The total pressure is 0 55 atm The container is heated to 1200K at which both gases decompose completely according to the equation 2NH3 g N2 g 3H g and N H g N g 2H g After complete decomposition the total 4 pressure at 1200K is found to be 5 5 atm Find the moles of N H4 in the original mixture A 30 B 25 C 40 D 75

An equilibrium reaction is as follows A B C D The reaction begins with concentrations of 0 80 for A and B with no C and D present Once the reaction proceeds to the right and reaches equilibrium the concentrations of C and D both 0 37 Determine the value of Kc reporting to two decimal places

constant change by this change in volume the equilibrium con 4 Would you expect the equilibrium constant for the reaction g 21 g to increase or decrease as temperature increases Why Hint The forward reaction is endothermic as energy is required to break 1 into I the reaction NOBr g NO g Br g K 0 15 atm at 90 C If 0 50 atr No No

13 5 points A 25 3mL sample of 0 110 M HCI is titrated with 0 256 M NaOH Calculate the pH after the addition of 47 7 mL of NaOH Hint Determine the equivalence point so you know where you are in the titration Report your answer with two places past the decimal point

What is the hybridization around the central atom in H S

9 4 points Identify the polyprotic acids Select all that apply Wrong answers are penalized HCIO3 HNO3 H3PO4 H CO3 HCI

21 5 points Calculate the H3O ion concentration in an aqueous solution with a pH of 2 39 at 25 C Report your answer in scientific notation with 2 places past the decimal point Write scientific notation in this format 1 23 10 1 Do not include a unit in your answer

4 3 Arrange the following acids in increasing acid strength There is no partial credit on this problem Strongest acid 2 1 HOBr Ka 2 5 x 10 eakest acid HC3H5O3 Ka 1 3 x 10 4 HCIO Ka 1 1 x 10 2 H3BO3 Ka 5 9 x 10 10

For the reaction given below 0 333 M A and 0 500M B are placed in an container A equilibrium the concentration of A is 0 150 M Complete the below table and determine the concentration of B at equilibrium Initial Change Equilibrium Your Answer A g 0 333M 0 150 M 2B g 0 500M C g 0 000M

Rank the following acids in order of increasing acid strength the top one is the strongest There is no partial credit for this problem Strongest acid 1 2 3 NH3 Weakest acid H O HF

In Beaker A an antacid tablet is added to 50 mL of 20 C water In Beaker B an antacid tablet is added 50 mL of 70 C water In which beaker will the reaction occur faster B both will occur at the same rate

12 5 points Determine the pH of a buffer solution containing 0 376 M benzoic acid C6H5COOH and 0 637 M sodium benzoate C6H5COONa Ka for benzoic acid is 6 3 x 10 5 Report your answer with two places past the decimal Tungu

The Ka for the weak acid HA is 2 48 10 9 Calculate the Kb for conjugate base A at 25 C Report your answer in scientific notation with two places past the decimal Use this format for scientific notation 1 23 10 1 Type your answer

Type your answer 17 5 points If the H3O ion concentration in an aqueous solution at 25 C has a value of 6 40 x 10 6 M what is the pOH of the solution Report your answer with two places past the decimal point Tyne your angu

Rank the following acid in order of increasing acid strength the top one is the strongest There is no partial credit on this problem Strongst acid 2 1 HBrO2 HBrO3

Acid Base Reaction Consider the following acid base equilibrium HC6H50 C4H7O2 C6H5O HC4H7O2 The position of the equilibrium lies to the left 8 4 points The strongest acid in this system is choose your answer strongest base in this system is choose your answer the

1 5 points The ionization constant Ka for weak acid HA is 1 79 x 10 11 What is the pH of a 0 5670 M solution of this acid The equation for the ionization of weak acid HA as follows HA aq H2O 1 H3O aq A aq Report your answer with two places past the decimal point Hint Use an ICE table

t a particular temperature K 3 1 for the reaction SO2 g NO2 g SO3 g NO g fall four gases had initial concentrations of 0 800 M calculate the equilibrium concentrations of the 50 M NO 503 NO M M M

In which of the following reactions will Kc Kp O 2 SO2 g O2 g 2 SO3 g O 4 NH3 g 3 O2 g 2 N2 g 6 H O g O SO3 g NO g SO2 g NO2 g O2 N2 g O2 g 2 N O g O None of the above reactions have Kc Kp

Determine the value of Ke for the following reaction if the equilibrium concentrations are as follows C3Hg 0 15 M 02 0 35 M CO 1 3 M H20 2 8 M C3H8 g 5 O2 g 3 CO2 g 4H O g O 6 7 103 6 1 9 10 4 O 1 7 105 X O 3 2 x 10 6 O 7 4 102

How do we know that ice melting is an endothermic process The products are higher in energy than the reactants The process releases heat The product has the same chemical formula but has a new state All the above are correct

In the ICE table started for calculating equilibrium concentrations of the reaction shown the three terms in the change row are I C E M 0 20 M x 2x x X X X X 2x x M 2L L 0 40 M X x x ML ML4 OM

Given these reactions and their equilibrium constants CO g 3 H g CH4 g H O g K 3 93 V 2 N g 3 2 H g NH g K 0 324 determine K for the following reaction CO g 2 NH3 g CH4 g H O g N g

An aqueous solution contains 0 375 M ethylamine C H5NH How many mL of 0 215 M nitric acid would have to be added to 250 mL of this solution in order to prepare a buffer with a pH of 10 500 ml

If Kp 2 for A g 2 B g what is the value of K for 2 B g A g 04 0 2 0 5 0 5 1 41

Consider the following reaction for which K 0 0136 at 731 K 2 HI g H g 1 g Which statement is always true regardless of the conditions temperature pressure etc O Ke 0 0136 OKp 0 0136 O Ke Qc O Kp Op O Kp K

The equilibrium constant of this process is Kp 5 29 at 300 K 2 A g B g C g Starting with 0 800 atm of A at 300 K what is the equilibrium pressure of C

Write the equilibrium expression Ke for the following equation 4 HCl aq O g 2 H O l 2 Cl g Edit Format Table

The reaction A g 2 B g is exothermic Identify the direction of the shift in equilibrium after each of the following changes Select increase A increase B right to product left to reactant no change Select Select increase T increase V

Question 11 1 p Dihydrogen phosphate H PO4 ionizes in water to form H O and HPO42 The equilibrium constant of this process is K 1 35 x 10 7 Determine the equilibrium concentration of H O in a solution that is initially 0 100 M H PO4 H PO4 aq H O 1 H O aq HPO4 aq O 1 35 x 10 7 M O 1 35 108 M O 1 16 x 104 M O 3 67 x 104 M 6 59 x 104 M

An equilibrium that strongly favours products has A value of K 1 A value of Q K A value of Q K A value of K 1

Consider the reaction of carbon dioxide and carbon tetrafluoride gas to form gaseous carbonyl fluoride COF2 CO g CF4 g 2 COF g K 0 50 at 1000 C Suppose that at one point during this reaction the concentration of COF is 0 12 M and the concentrations of the reactants are each 0 18 M In which direction will the reaction proceed to achieve equilibrium

For the reversible reaction between reactants A and B to form products C and D which species are present at equilibrium A B C D

Consider the reaction of carbon monoxide and chlorine gases to form gaseous phosgene COC1 CO g Cl g COCl g Suppose that equal amounts of CO and Cl are mixed at 800 C The resulting equilibrium concentration of COCI is 0 125 M and the equilibrium concentration of Cl is 0 0240 M Calculate K and K for this reaction at 800 C

2 What is the pH of a 0 00056 M solution of HCI 2 pts

At a certain temperature the equilibrium constant Ke for this reaction is 53 3 H g 1 g 2 HI g K 53 3 At this temperature 0 500 mol H and 0 500 mol I were placed in a 1 00 L container to react What concentration of E present at equilibrium HI

10 5 points A student is preparing a study of the reaction 2CO2 g 2CO g O2 g for which Kc 24 5 at 887 C What is the value of Kp at that same temperature Keep the answer with 2 decimal places Type your answer A

5 50 0mL of 0 10M HCI solution is mixed with 80 0mL 0 035M NH aqueous solution What is the pH of the resulting solution pH 1 77 AS

3 4 points What factors influence the effectiveness of molecular collisions in producing chemical change Select all that apply The orientation of the reactants None of these factors apply The molar mass of the reactants The activation energy The pressure