Arrange the following in increasing order of pH.
KN03(aq), CH3COONa(aq), NH4Cl(aq), C6H5COONH4(aq)
Classify the following species into Lewis acids and Lewis bases and show how these can act as Lewis acid/Lewis base?
(a) OH– ions (b) F– (c) H+ (d) BCl3
For the equilibrium 2 NOCl(g)——-> 2NO(g) + Cl2(g) the value of the equilibrium constant Kc is 3.75 x 10-6 at 1069 K. Calculate the Kp for the reaction at this temperature?
A sparingly soluble salt gets precipitated only when the product of concentration of its ions in the solution (Qsp) becomes greater than its solubility product. If the solubility of BaS04 in water is 8 x 10-4 mol dm-3, calculate its solubility in 0.01 mol dm-3 of H2S04.
The equilibrium constant expression for a gas reaction is,
Write the balanced chemical equation corresponding to this expression.
The species H20, HCO3–, HSO4– and NH3 can act both as Bronsted acid and base. For each case, give the corresponding conjugate acid and base.
pH of a solution of a strong acid is 5.0. What will be the pH of the solution obtained after diluting the given solution a 100 times?
Calculate the volume of water required to dissolve 0.1 g lead (II) chloride to get a saturated solution. (Ksp of PbCl2 = 3.2 x 10-8, atomic mass of Pb = 207 u).
The degree of ionization of a 0.1 M bromoacetic acid solution is 0.132. Calculate the pH of the solution and the PKa of bromoacetic acid.
The pH of0.005 M codeine (C18H21N03) solution is 9.95. Calculate the ionization constant and PKb.
Given the equilibrium N2O4 (g) ——->2NO2 (g) K=0.15 atm at 298 K
(a) What is Kp using pressure in torr?
(b) What is Kc using units of moles per litre.
BF3 does not have proton but still acts as an acid and reacts with NH3. Why is it so? What type of bond is formed between the two?
Ionization constant of a weak base MOH, is given by the expression
Values of ionization constant of some weak bases at a particular temperature are given below:
| Base | Dimethylamine | Urea | Pyridine | Ammonia |
| 5.4 x 10-4 | 1.3 x 10-14 | 1.77 x lO-9 | 1.77 xlO-5 |
Arrange the bases in decreasing order of the extent of their ionization at equilibrium. Which of the above base is the strongest?
Explain why pure liquids and solids can be ignored while writing the value of equilibrium constants.
Calculate the pH of the following solutions:
(a) 2g ofTlOH dissolved in water to give 2 litre of the solution
(b) 0.3 g of Ca(OH)2 dissolved in water to give 500 mL of the solution
(c) 0.3 g of NaOH dissolved in water to give 200 mL of the solution
(d) l mL of 13.6 M HCl is diluted with water to give 1 litre of the solution.
What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of ICl was 0.78 M?
What is the effect of:
(i) addition of H2 (ii) addition of CH3OH
(iii) removal of CO (iv) removal of CH3OH
In the reaction A + B———> C + D, what will happen to the equilibrium if concentration of A is increased?
(b) The equilibrium constant for a reaction is 2 x 10-23 at 25 °C and 2 x 10-2 at 50 °C. Is the reaction endothermic or exothermic?
(c) Mention at least three ways by which the concentration of S03 can be increased in the following reaction in a state of equilibrium.
For the reaction: N2(g) + 3H2(g) ⇌2NH3(g) equilibrium constant,
Some reactions are written below in Column I and their equilibrium constants in terms of Kc are written in Column II. Match the following reactions with the corresponding equilibrium constant.
One of the reactions that takes place in producing steel from iron ore is the reduction of iron
(II) oxide by carbon monoxide to give iron metal and C02
FeO(s) + CO(g) ———>Fe(s) + C02(g) ; Kp = 0.265 atm at 1050 K
What are the equilibrium partial pressures of CO and C02 at 1050 K if the initial pressures are: PCO = 1.4 atm and PCO2 = 0.80 atm?
Bromine monochloride (BrCl ) decomposes into bromine and chlorine and reaches the equilibrium:
The value of Kc is 32 at 500 K. If initially pure BrCl is present at a concentration of 3.3 x10-3mol L-1what is its molar concentration in the mixture at equilibrium?
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 H2 In second stage, CO formed in first stage is reacted with more steam in water gas shift reaction.
If a reaction vessel at 400 °C is charged with an equimolar mixture of CO and steam so that PCO = PH2O = 4.0 bar, what will be the partial pressure of H2 at equilibrium? Kp = 0.1 at 400 °C.
What is meant by conjugate acid-base pair? Find the conjugate acid/base for the following species: HNO2, CH–, HClO4 , OH–, CO32-, S2-
The pH of a sample of vinegar is 3.76. Calculate the concentration of hydrogen ion in it.
The ionization constant of HF, HCOOH and HCN at 298 K are is 6.8 x 10-4 , 1.8 x 10-4 and 4.8 x 10-9 respectively, Calculate the ionization constant of the corresponding conjugate base.
Conjugate acid of a weak base is always stronger. What will be the decreasing order of basic strength of the following conjugate bases?
OH–, RO–, ch3coo– , cl–
A reaction between ammonia and boron trifluoride is given below:
:NH3 + BF3 →H3N : BF3
Identify the acid and base in this reaction. Which theory explains it? What is the hybridization of B and N in the reactants?
Match the following equilibria with the corresponding condition
| Column I | Column II | ||
| (i) | Liquid⇌Vapour | (a) | Saturated solution |
| (ii) | Solid ⇌Liquid | (b) | Boiling point |
| (iii) | Solid ⇌Vapour | (c) | Sublimation point |
| (iv) | Solute(s) ⇌Solute (solution) | (d) | Melting point ‘ |
| (e) | Unsaturated solution | ||
Reaction between nitrogen and oxygen takes place as follows:
If a mixture of 0.482 mol of N2 and 0.933 mol of O2 is placed in a reaction vessel of volume 10 L and allowed to form N2O at a temperature for which Kc – 2.0 x 10-37, determine the composition of the equilibrium mixture.
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 bp increasing the volume?
The ionization constant of acetic acid is 1.74 x 10-5. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ions in the solution and its pH.
It has been found that the pH of a 0.01 M solution of an organic acid is 4.15. Calculate the concentration of the anion, the ionization constant of the acid and its PKa.
