Q6.13:

The equilibrium constant expression for a gas reaction is, $K_c = \frac{[NH_3]^4 [O_2]^5}{[NO]^4 [H_2O]^6}$ Write the balanced chemical equation corresponding to this expression.

More Questions from Class 11 Chemistry Equilibrium EXERCISES

• Q6.1(a): A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased. a) What is the initial effect of the change on vapour pressure?
• Q6.1(b): A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased. b) How do rates of evaporation and condensation change initially?
• Q6.1(c): A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased. c) What happens when equilibrium is restored finally and what will be the final vapour pressure?
• Q6.10: At 450K, $K_p= 2.0 \times 10^{10}/bar$ for the given reaction at equilibrium. $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3 (g)$ What is $K_c$ at this temperature ?
• Q6.11: A sample of $HI(g)$ is placed in flask at a pressure of 0.2 atm. At equilibrium the partial pressure of $HI(g)$ is 0.04 atm. What is $K_p$ for the given equilibrium ? $2HI (g) \rightleftharpoons H_2 (g) + I_2 (g)$
• Q6.12: A mixture of 1.57 mol of $N_2$, 1.92 mol of $H_2$ and 8.13 mol of $NH_3$ is introduced into a 20 L reaction vessel at 500 K. At this temperature, the equilibrium constant, $K_c$ for the reaction $N_2 (g) + 3H_2 (g) \rightleftharpoons 2NH_3 (g)$ is $1.7 \times 10^2$. Is the reaction mixture at equilibrium? If not, what is the direction of the net reaction?
• Q6.14: One mole of $H_2O$ and one mole of CO are taken in 10 L vessel and heated to 725 K. At equilibrium 40% of water (by mass) reacts with CO according to the equation, $H_2O (g) + CO (g) \rightleftharpoons H_2 (g) + CO_2 (g)$ Calculate the equilibrium constant for the reaction.
• Q6.15: At 700 K, equilibrium constant for the reaction: $H_2 (g) + I_2 (g) \rightleftharpoons 2HI (g)$ is 54.8. If 0.5 mol $L^{-1}$ of $HI(g)$ is present at equilibrium at 700 K, what are the concentration of $H_2(g)$ and $I_2(g)$ assuming that we initially started with $HI(g)$ and allowed it to reach equilibrium at 700K?
• Q6.16: What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of ICl was 0.78 M ? $2ICl (g) \rightleftharpoons I_2 (g) + Cl_2 (g)$; $K_c = 0.14$
• Q6.17: $K_p = 0.04$ atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of $C_2H_6$ when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium? $C_2H_6 (g) \rightleftharpoons C_2H_4 (g) + H_2 (g)$
• Q6.18(i): Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as: $CH_3COOH (l) + C_2H_5OH (l) \rightleftharpoons CH_3COOC_2H_5 (l) + H_2O (l)$ (i) Write the concentration ratio (reaction quotient), $Q_c$, for this reaction (note: water is not in excess and is not a solvent in this reaction)
• Q6.18(ii): Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as: $CH_3COOH (l) + C_2H_5OH (l) \rightleftharpoons CH_3COOC_2H_5 (l) + H_2O (l)$ (ii) At 293 K, if one starts with 1.00 mol of acetic acid and 0.18 mol of ethanol, there is 0.171 mol of ethyl acetate in the final equilibrium mixture. Calculate the equilibrium constant.
• Q6.18(iii): Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as: $CH_3COOH (l) + C_2H_5OH (l) \rightleftharpoons CH_3COOC_2H_5 (l) + H_2O (l)$ (iii) Starting with 0.5 mol of ethanol and 1.0 mol of acetic acid and maintaining it at 293 K, 0.214 mol of ethyl acetate is found after sometime. Has equilibrium been reached?
• Q6.19: A sample of pure $PCl_5$ was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of $PCl_5$ was found to be $0.5 \times 10^{-1}$ mol $L^{-1}$. If value of $K_c$ is $8.3 \times 10^{-3}$, what are the concentrations of $PCl_3$ and $Cl_2$ at equilibrium? $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2(g)$
• Q6.2: What is $K_c$ for the following equilibrium when the equilibrium concentration of each substance is: $[SO_2]$= 0.60M, $[O_2]$ = 0.82M and $[SO_3]$ = 1.90M ? $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$
• Q6.20: One of the reaction that takes place in producing steel from iron ore is the reduction of iron(II) oxide by carbon monoxide to give iron metal and $CO_2$. $FeO (s) + CO (g) \rightleftharpoons Fe (s) + CO_2 (g)$; $K_p = 0.265$ atm at 1050K What are the equilibrium partial pressures of CO and $CO_2$ at 1050 K if the initial partial pressures are: $p_{CO}$= 1.4 atm and $p_{CO_2}$ = 0.80 atm?
• Q6.21: Equilibrium constant, $K_c$ for the reaction $N_2 (g) + 3H_2 (g) \rightleftharpoons 2NH_3 (g)$ at 500 K is 0.061 At a particular time, the analysis shows that composition of the reaction mixture is 3.0 mol $L^{-1}$ $N_2$, 2.0 mol $L^{-1}$ $H_2$ and 0.5 mol $L^{-1}$ $NH_3$. Is the reaction at equilibrium? If not in which direction does the reaction tend to proceed to reach equilibrium?
• Q6.22: Bromine monochloride, BrCl decomposes into bromine and chlorine and reaches the equilibrium: $2BrCl (g) \rightleftharpoons Br_2 (g) + Cl_2 (g)$ for which $K_c= 32$ at 500 K. If initially pure BrCl is present at a concentration of $3.3 \times 10^{-3}$ mol $L^{-1}$, what is its molar concentration in the mixture at equilibrium?
• Q6.23: At 1127 K and 1 atm pressure, a gaseous mixture of CO and $CO_2$ in equilibrium with soild carbon has 90.55% CO by mass $C (s) + CO_2 (g) \rightleftharpoons 2CO (g)$ Calculate $K_c$ for this reaction at the above temperature.
• Q6.24(a): Calculate a) $\Delta G^{\circ}$ for the formation of $NO_2$ from NO and $O_2$ at 298K $NO (g) + \frac{1}{2} O_2 (g) \rightleftharpoons NO_2 (g)$ where $\Delta_f G^{\circ} (NO_2) = 52.0$ kJ/mol $\Delta_f G^{\circ} (NO) = 87.0$ kJ/mol $\Delta_f G^{\circ} (O_2) = 0$ kJ/mol
• Q6.24(b): Calculate b) the equilibrium constant for the formation of $NO_2$ from NO and $O_2$ at 298K $NO (g) + \frac{1}{2} O_2 (g) \rightleftharpoons NO_2 (g)$ where $\Delta_f G^{\circ} (NO_2) = 52.0$ kJ/mol $\Delta_f G^{\circ} (NO) = 87.0$ kJ/mol $\Delta_f G^{\circ} (O_2) = 0$ kJ/mol
• Q6.25(a): Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume? (a) $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$
• Q6.25(b): Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume? (b) $CaO (s) + CO_2 (g) \rightleftharpoons CaCO_3 (s)$
• Q6.25(c): Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume? (c) $3Fe (s) + 4H_2O (g) \rightleftharpoons Fe_3O_4 (s) + 4H_2 (g)$
• Q6.26(i): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (i) $COCl_2 (g) \rightleftharpoons CO (g) + Cl_2 (g)$
• Q6.26(ii): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (ii) $CH_4 (g) + 2S_2 (g) \rightleftharpoons CS_2 (g) + 2H_2S (g)$
• Q6.26(iii): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (iii) $CO_2 (g) + C (s) \rightleftharpoons 2CO (g)$
• Q6.26(iv): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (iv) $2H_2 (g) + CO (g) \rightleftharpoons CH_3OH (g)$
• Q6.26(v): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (v) $CaCO_3 (s) \rightleftharpoons CaO (s) + CO_2 (g)$
• Q6.26(vi): Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction. (vi) $4 NH_3 (g) + 5O_2 (g) \rightleftharpoons 4NO (g) + 6H_2O(g)$
• Q6.27: The equilibrium constant for the following reaction is $1.6 \times 10^5$ at 1024K $H_2(g) + Br_2(g) \rightleftharpoons 2HBr(g)$ Find the equilibrium pressure of all gases if 10.0 bar of HBr is introduced into a sealed container at 1024K.
• Q6.28(a): Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: $CH_4 (g) + H_2O (g) \rightleftharpoons CO (g) + 3H_2 (g)$ (a) Write as expression for $K_p$ for the above reaction.
• Q6.28(b)(i): Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: $CH_4 (g) + H_2O (g) \rightleftharpoons CO (g) + 3H_2 (g)$ (b) How will the values of $K_p$ and composition of equilibrium mixture be affected by (i) increasing the pressure
• Q6.28(b)(ii): Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: $CH_4 (g) + H_2O (g) \rightleftharpoons CO (g) + 3H_2 (g)$ (b) How will the values of $K_p$ and composition of equilibrium mixture be affected by (ii) increasing the temperature
• Q6.28(b)(iii): Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction: $CH_4 (g) + H_2O (g) \rightleftharpoons CO (g) + 3H_2 (g)$ (b) How will the values of $K_p$ and composition of equilibrium mixture be affected by (iii) using a catalyst?
• Q6.29(a): Describe the effect of: a) addition of $H_2$ on the equilibrium of the reaction: $2H_2(g) + CO (g) \rightleftharpoons CH_3OH (g)$
• Q6.29(b): Describe the effect of: b) addition of $CH_3OH$ on the equilibrium of the reaction: $2H_2(g) + CO (g) \rightleftharpoons CH_3OH (g)$
• Q6.29(c): Describe the effect of: c) removal of CO on the equilibrium of the reaction: $2H_2(g) + CO (g) \rightleftharpoons CH_3OH (g)$
• Q6.29(d): Describe the effect of: d) removal of $CH_3OH$ on the equilibrium of the reaction: $2H_2(g) + CO (g) \rightleftharpoons CH_3OH (g)$
• Q6.3: At a certain temperature and total pressure of $10^5$Pa, iodine vapour contains 40% by volume of $I$ atoms $I_2 (g) \rightleftharpoons 2I (g)$ Calculate $K_p$ for the equilibrium.
• Q6.30(a): At 473 K, equilibrium constant $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as, $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$ $\Delta_r H^{\circ} = 124.0$ kJ $mol^{-1}$ a) write an expression for $K_c$ for the reaction.
• Q6.30(b): At 473 K, equilibrium constant $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as, $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$ $\Delta_r H^{\circ} = 124.0$ kJ $mol^{-1}$ b) what is the value of $K_c$ for the reverse reaction at the same temperature?
• Q6.30(c)(i): At 473 K, equilibrium constant $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as, $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$ $\Delta_r H^{\circ} = 124.0$ kJ $mol^{-1}$ c) what would be the effect on $K_c$ if (i) more $PCl_5$ is added
• Q6.30(c)(ii): At 473 K, equilibrium constant $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as, $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$ $\Delta_r H^{\circ} = 124.0$ kJ $mol^{-1}$ c) what would be the effect on $K_c$ if (ii) pressure is increased
• Q6.30(c)(iii): At 473 K, equilibrium constant $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as, $PCl_5 (g) \rightleftharpoons PCl_3 (g) + Cl_2 (g)$ $\Delta_r H^{\circ} = 124.0$ kJ $mol^{-1}$ c) what would be the effect on $K_c$ if (iii) the temperature is increased ?
• Q6.31: Dihydrogen gas used in Haber’s process is produced by reacting methane from natural gas with high temperature steam. The first stage of two stage reaction involves the formation of CO and $H_2$. In second stage, CO formed in first stage is reacted with more steam in water gas shift reaction, $CO (g) + H_2O (g) \rightleftharpoons CO_2 (g) + H_2 (g)$ If a reaction vessel at $400^{\circ}C$ is charged with an equimolar mixture of CO and steam such that $p_{CO} = p_{H_2O} = 4.0$ bar, what will be the partial pressure of $H_2$ at equilibrium? $K_p= 10.1$ at $400^{\circ}C$
• Q6.32(a): Predict which of the following reaction will have appreciable concentration of reactants and products: a) $Cl_2 (g) \rightleftharpoons 2Cl (g) \quad K_c = 5 \times 10^{-39}$
• Q6.32(b): Predict which of the following reaction will have appreciable concentration of reactants and products: b) $Cl_2 (g) + 2NO (g) \rightleftharpoons 2NOCl (g) \quad K_c = 3.7 \times 10^8$
• Q6.32(c): Predict which of the following reaction will have appreciable concentration of reactants and products: c) $Cl_2 (g) + 2NO_2 (g) \rightleftharpoons 2NO_2Cl (g) \quad K_c = 1.8$
• Q6.33: The value of $K_c$ for the reaction $3O_2 (g) \rightleftharpoons 2O_3 (g)$ is $2.0 \times 10^{-50}$ at $25^{\circ}C$. If the equilibrium concentration of $O_2$ in air at $25^{\circ}C$ is $1.6 \times 10^{-2}$, what is the concentration of $O_3$?
• Q6.34: The reaction, $CO(g) + 3H_2(g) \rightleftharpoons CH_4(g) + H_2O(g)$ is at equilibrium at 1300 K in a 1L flask. It also contain 0.30 mol of CO, 0.10 mol of $H_2$ and 0.02 mol of $H_2O$ and an unknown amount of $CH_4$ in the flask. Determine the concentration of $CH_4$ in the mixture. The equilibrium constant, $K_c$ for the reaction at the given temperature is 3.90.
• Q6.35: What is meant by the conjugate acid-base pair? Find the conjugate acid/base for the following species: $HNO_2$, $CN^{-}$, $HClO_4$, $F^{-}$, $OH^{-}$, $CO_3^{2-}$, and $S^{2-}$
• Q6.36: Which of the followings are Lewis acids? $H_2O$, $BF_3$, $H^{+}$, and $NH_4^{+}$
• Q6.37: What will be the conjugate bases for the Brönsted acids: HF, $H_2SO_4$ and $HCO_3^{-}$?
• Q6.38: Write the conjugate acids for the following Brönsted bases: $NH_2^{-}$, $NH_3$ and $HCOO^{-}$.
• Q6.39: The species: $H_2O$, $HCO_3^{-}$, $HSO_4^{-}$ and $NH_3$ can act both as Brönsted acids and bases. For each case give the corresponding conjugate acid and base.
• Q6.4(i): Write the expression for the equilibrium constant, $K_c$ for each of the following reactions: (i) $2NOCl (g) \rightleftharpoons 2NO (g) + Cl_2 (g)$
• Q6.4(ii): Write the expression for the equilibrium constant, $K_c$ for each of the following reactions: (ii) $2Cu(NO_3)_2 (s) \rightleftharpoons 2CuO (s) + 4NO_2 (g) + O_2 (g)$
• Q6.4(iii): Write the expression for the equilibrium constant, $K_c$ for each of the following reactions: (iii) $CH_3COOC_2H_5(aq) + H_2O(l) \rightleftharpoons CH_3COOH (aq) + C_2H_5OH (aq)$
• Q6.4(iv): Write the expression for the equilibrium constant, $K_c$ for each of the following reactions: (iv) $Fe^{3+} (aq) + 3OH^{-} (aq) \rightleftharpoons Fe(OH)_3 (s)$
• Q6.4(v): Write the expression for the equilibrium constant, $K_c$ for each of the following reactions: (v) $I_2 (s) + 5F_2 \rightleftharpoons 2IF_5$
• Q6.40(a): Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base: (a) $OH^{-}$
• Q6.40(b): Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base: (b) $F^{-}$
• Q6.40(c): Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base: (c) $H^{+}$
• Q6.40(d): Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base: (d) $BCl_3$.
• Q6.41: The concentration of hydrogen ion in a sample of soft drink is $3.8 \times 10^{-3}$ M. What is its pH?
• Q6.42: The pH of a sample of vinegar is 3.76. Calculate the concentration of hydrogen ion in it.
• Q6.43: The ionization constant of HF, HCOOH and HCN at 298K are $6.8 \times 10^{-4}$, $1.8 \times 10^{-4}$ and $4.8 \times 10^{-9}$ respectively. Calculate the ionization constants of the corresponding conjugate base.
• Q6.44: The ionization constant of phenol is $1.0 \times 10^{-10}$. What is the concentration of phenolate ion in 0.05 M solution of phenol? What will be its degree of ionization if the solution is also 0.01M in sodium phenolate?
• Q6.45: The first ionization constant of $H_2S$ is $9.1 \times 10^{-8}$. Calculate the concentration of $HS^{-}$ ion in its 0.1M solution. How will this concentration be affected if the solution is 0.1M in HCl also? If the second dissociation constant of $H_2S$ is $1.2 \times 10^{-13}$, calculate the concentration of $S^{2-}$ under both conditions.
• Q6.46: The ionization constant of acetic acid is $1.74 \times 10^{-5}$. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ion in the solution and its pH.
• Q6.47: It has been found that the pH of a 0.01M solution of an organic acid is 4.15. Calculate the concentration of the anion, the ionization constant of the acid and its $pK_a$.
• Q6.48(a): Assuming complete dissociation, calculate the pH of the following solutions: (a) 0.003 M HCl
• Q6.48(b): Assuming complete dissociation, calculate the pH of the following solutions: (b) 0.005 M NaOH
• Q6.48(c): Assuming complete dissociation, calculate the pH of the following solutions: (c) 0.002 M HBr
• Q6.48(d): Assuming complete dissociation, calculate the pH of the following solutions: (d) 0.002 M KOH
• Q6.49(a): Calculate the pH of the following solutions: a) 2 g of TlOH dissolved in water to give 2 litre of solution.
• Q6.49(b): Calculate the pH of the following solutions: b) 0.3 g of $Ca(OH)_2$ dissolved in water to give 500 mL of solution.
• Q6.49(c): Calculate the pH of the following solutions: c) 0.3 g of NaOH dissolved in water to give 200 mL of solution.
• Q6.49(d): Calculate the pH of the following solutions: d) 1mL of 13.6 M HCl is diluted with water to give 1 litre of solution.
• Q6.5(i): Find out the value of $K_c$ for each of the following equilibria from the value of $K_p$: (i) $2NOCl (g) \rightleftharpoons 2NO (g) + Cl_2 (g)$; $K_p= 1.8 \times 10^{-2}$ at 500 K
• Q6.5(ii): Find out the value of $K_c$ for each of the following equilibria from the value of $K_p$: (ii) $CaCO_3 (s) \rightleftharpoons CaO(s) + CO_2(g)$; $K_p= 167$ at 1073 K
• Q6.50: The degree of ionization of a 0.1M bromoacetic acid solution is 0.132. Calculate the pH of the solution and the $pK_a$ of bromoacetic acid.
• Q6.51: The pH of 0.005M codeine ($C_{18}H_{21}NO_3$) solution is 9.95. Calculate its ionization constant and $pK_b$.
• Q6.52: What is the pH of 0.001M aniline solution? The ionization constant of aniline can be taken from Table 6.7. Calculate the degree of ionization of aniline in the solution. Also calculate the ionization constant of the conjugate acid of aniline.
• Q6.53(a): Calculate the degree of ionization of 0.05M acetic acid if its $pK_a$ value is 4.74. How is the degree of dissociation affected when its solution also contains (a) 0.01M in HCl ?
• Q6.53(b): Calculate the degree of ionization of 0.05M acetic acid if its $pK_a$ value is 4.74. How is the degree of dissociation affected when its solution also contains (b) 0.1M in HCl ?
• Q6.54: The ionization constant of dimethylamine is $5.4 \times 10^{-4}$. Calculate its degree of ionization in its 0.02M solution. What percentage of dimethylamine is ionized if the solution is also 0.1M in NaOH?
• Q6.55(a): Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below: (a) Human muscle-fluid, 6.83
• Q6.55(b): Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below: (b) Human stomach fluid, 1.2
• Q6.55(c): Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below: (c) Human blood, 7.38
• Q6.55(d): Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below: (d) Human saliva, 6.4.
• Q6.56: The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.
• Q6.57: If 0.561 g of KOH is dissolved in water to give 200 mL of solution at 298 K. Calculate the concentrations of potassium, hydrogen and hydroxyl ions. What is its pH?
• Q6.58: The solubility of $Sr(OH)_2$ at 298 K is 19.23 g/L of solution. Calculate the concentrations of strontium and hydroxyl ions and the pH of the solution.
• Q6.59: The ionization constant of propanoic acid is $1.32 \times 10^{-5}$. Calculate the degree of ionization of the acid in its 0.05M solution and also its pH. What will be its degree of ionization if the solution is 0.01M in HCl also?
• Q6.6: For the following equilibrium, $K_c= 6.3 \times 10^{14}$ at 1000 K $NO (g) + O_3 (g) \rightleftharpoons NO_2 (g) + O_2 (g)$ Both the forward and reverse reactions in the equilibrium are elementary bimolecular reactions. What is $K_c$, for the reverse reaction?
• Q6.60: The pH of 0.1M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.
• Q6.61: The ionization constant of nitrous acid is $4.5 \times 10^{-4}$. Calculate the pH of 0.04 M sodium nitrite solution and also its degree of hydrolysis.
• Q6.62: A 0.02M solution of pyridinium hydrochloride has pH = 3.44. Calculate the ionization constant of pyridine.
• Q6.63: Predict if the solutions of the following salts are neutral, acidic or basic: NaCl, KBr, NaCN, $NH_4NO_3$, $NaNO_2$ and KF
• Q6.64: The ionization constant of chloroacetic acid is $1.35 \times 10^{-3}$. What will be the pH of 0.1M acid and its 0.1M sodium salt solution?
• Q6.65: Ionic product of water at 310 K is $2.7 \times 10^{-14}$. What is the pH of neutral water at this temperature?
• Q6.66(a): Calculate the pH of the resultant mixtures: a) 10 mL of 0.2M $Ca(OH)_2$ + 25 mL of 0.1M HCl
• Q6.66(b): Calculate the pH of the resultant mixtures: b) 10 mL of 0.01M $H_2SO_4$ + 10 mL of 0.01M $Ca(OH)_2$
• Q6.66(c): Calculate the pH of the resultant mixtures: c) 10 mL of 0.1M $H_2SO_4$ + 10 mL of 0.1M KOH
• Q6.67: Determine the solubilities of silver chromate, barium chromate, ferric hydroxide, lead chloride and mercurous iodide at 298K from their solubility product constants given in Table 6.9. Determine also the molarities of individual ions.
• Q6.68: The solubility product constant of $Ag_2CrO_4$ and AgBr are $1.1 \times 10^{-12}$ and $5.0 \times 10^{-13}$ respectively. Calculate the ratio of the molarities of their saturated solutions.
• Q6.69: Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate? (For cupric iodate $K_{sp} = 7.4 \times 10^{-8}$ ).
• Q6.7: Explain why pure liquids and solids can be ignored while writing the equilibrium constant expression?
• Q6.70: The ionization constant of benzoic acid is $6.46 \times 10^{-5}$ and $K_{sp}$ for silver benzoate is $2.5 \times 10^{-13}$. How many times is silver benzoate more soluble in a buffer of pH 3.19 compared to its solubility in pure water?
• Q6.71: What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide so that when mixed in equal volumes, there is no precipitation of iron sulphide? (For iron sulphide, $K_{sp} = 6.3 \times 10^{-18}$).
• Q6.72: What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, $K_{sp}$ is $9.1 \times 10^{-6}$).
• Q6.73: The concentration of sulphide ion in 0.1M HCl solution saturated with hydrogen sulphide is $1.0 \times 10^{-19}$ M. If 10 mL of this is added to 5 mL of 0.04 M solution of the following: $FeSO_4$, $MnCl_2$, $ZnCl_2$ and $CdCl_2$. in which of these solutions precipitation will take place?
• Q6.8: Reaction between $N_2$ and $O_2$ takes place as follows: $2N_2 (g) + O_2 (g) \rightleftharpoons 2N_2O (g)$ If a mixture of 0.482 mol $N_2$ and 0.933 mol of $O_2$ is placed in a 10 L reaction vessel and allowed to form $N_2O$ at a temperature for which $K_c= 2.0 \times 10^{-37}$, determine the composition of equilibrium mixture.
• Q6.9: Nitric oxide reacts with $Br_2$ and gives nitrosyl bromide as per reaction given below: $2NO (g) + Br_2 (g) \rightleftharpoons 2NOBr (g)$ When 0.087 mol of NO and 0.0437 mol of $Br_2$ are mixed in a closed container at constant temperature, 0.0518 mol of NOBr is obtained at equilibrium. Calculate equilibrium amount of NO and $Br_2$.