Problem 84
An aqucous solution of hydrogen sulphide shows the cquilibrium \(\mathrm{II}_{2} \mathrm{~S} \rightleftharpoons \mathrm{II}^{-} \mathrm{I} \mathrm{IIS}^{-}\) If dilute hydrochloric acid is added to an aqucous solution of hydrogen sulphide without any change in temperature, then (1) the equilibrium constant will change (2) the concentration of HS will increase (3) the concentration of nondissociated hydrogen sulphide will decrease (4) the concentration of HS will decrease
Problem 85
Oxidation of \(\mathrm{SO}_{2}\) to \(\mathrm{SO}_{3}\) by \(\mathrm{O}_{2}\) is an cxothermic reaction. The yicld of \(\mathrm{SO}_{3}\) will be maximum when(1) Temperature is increased and pressure is kept constant. (2) Temperature is reduced and pressure is increased. (3) Both temperature and pressure are increased. (4) Both temperature and pressure are reduced.
Problem 86
\begin{aligned} &\text { The hydrolysis constant of a salt of weak acid }\\\ &\left(K_{\mathrm{a}}=2 \times 10^{-6}\right) \text { and of a weak basc }\left(K_{\mathrm{b}}=5 \times 10^{-7}\right) \text { is } \end{aligned}(1) 10 (2) \(10^{2}\) (3) \(2 \times 10^{2}\) (4) \(5 \times 10^{3}\)
Problem 86
For which reaction high pressure and high temperature is helpful in obtaining a high cquilibrium yicld? (1) \(2 \mathrm{NF}_{3}(\mathrm{~g}) \rightleftharpoons \mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{~F}_{2}(\mathrm{~g}) \quad 54.40 \mathrm{kcal}\) (2) \(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{II}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NI}_{3}(\mathrm{~g})+22.08 \mathrm{kcal}\) (3) \(\mathrm{Cl}_{2}(\mathrm{~g})+2 \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{ClO}_{3}(\mathrm{~g}) \quad 49.4 \mathrm{kcal}\) (4) \(2 \mathrm{Cl}_{2} \mathrm{O}_{7}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{Cl}_{2}(\mathrm{~g}) \times 7 \mathrm{O}_{2}(\mathrm{~g})+126.8 \mathrm{kcal}\)
Problem 87
The hydrolysis constant \(K_{h}\) of a salt of sodium hydroxidc and weak acid (IIX) if the \(K_{a}\) of the acid is \(5 \times 10^{-6}\) is (1) \(2 \times 10^{-8}\) (2) \(5 \times 10^{-6}\) (3) \(2.5 \times 10^{-7}\) (4) \(5 \times 10^{-9}\)
Problem 87
Which oxide of nitrogen is the most stable? (1) \(2 \mathrm{NO}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{N}_{2}(\mathrm{~g})+2 \mathrm{O}(\mathrm{g}) \mathrm{k}=6.7 \times 10^{6} \mathrm{~mol}\) litre (2) \(2 \mathrm{NO}(\mathrm{g}) \rightleftharpoons \mathrm{N}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \mathrm{k}=2.2 \times 10^{30} \mathrm{~mol}\) litre (3) \(2 \mathrm{~N}_{2} \mathrm{O}_{5}(\mathrm{~g}) \rightleftharpoons \mathrm{N}_{2}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \mathrm{k}=1.2 \times 10^{34}\) mol litre (4) \(2 \mathrm{~N}_{2} \mathrm{O}(\mathrm{g}) \rightleftharpoons 2 \mathrm{~N}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \mathrm{k}=3.5 \times 10^{23}\) mol litre
Problem 90
In a vessel containing \(\mathrm{SO}_{3}, \mathrm{SO}_{2}\) and \(\mathrm{O}_{2}\) at equilibrium some helium gas is introduced so that the total pressure increases while temperature and volume remains constant. According to Le Chatelier's principle, the dissociation of \(\mathrm{SO}_{3}\) (1) increases (2) decreases (3) remains unaltered (4) changes unpredictably
Problem 92
The most important buffer in blood consists of (1) \(\mathrm{HCl}\) and \(\mathrm{Cl}\) (2) \(\mathrm{H}_{2} \mathrm{CO}_{3}\) and \(\mathrm{HCO}_{3}\) (3) \(\mathrm{H}_{2} \mathrm{CO}_{3}\) and \(\mathrm{Cl}\) (4) \(\mathrm{HCl}\) and \(\mathrm{HCO}_{3}\)
Problem 92
Which information can be obtained from Le Chatelier's principle? (1) Shift in equilibrium position on changing \(P, T\) and concentration (2) Dissociation constant of weak acid (3) Energy change in reaction (4) Equilibrium constant of a chemical reaction
Problem 94
\(\Lambda\) chemist who is concerned with large-scale manufacture of useful compounds is primarily intcrested in (1) minimizing the cncrgy consumption (2) maximizing the backward reaction (3) minimizing the reverse reaction (4) decrcasing the acidity of the product
