School & Entrance Prep

The molar solubility (in $\text{mol L}^{-1}$) of a sparingly soluble salt $\text{MX}_4$ is '$s$'. The corresponding solubility product is $K_{sp}$. '$s$' is given in term of $K_{sp}$ by the relation:

In a saturated solution of the sparingly soluble strong electrolyte $\text{AgIO}_3$ (molecular mass = 283) the equilibrium which sets in is $\text{AgIO}_3(s) \rightleftharpoons \text{Ag}^+(aq) + \text{IO}_3^-(aq)$ If the solubility product constant $K_{sp}$ of $\text{AgIO}_3$ at a given temperature is $1.0 \times 10^{-8}$, what is the mass of $\text{AgIO}_3$ contained in 100 mL of its saturated solution?

The solubility in water of a sparingly soluble salt $\text{AB}_2$ is $1.0 \times 10^{-5}\text{ mol L}^{-1}$. Its solubility product will be

The equilibrium constant for the reaction $\text{N}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{NO}(g)$ at temperature T is $4 \times 10^{-4}$. The value of $K_c$ for the reaction $\text{NO}(g) \rightleftharpoons \dfrac{1}{2}\text{N}_2(g) + \dfrac{1}{2}\text{O}_2(g)$ at the same temperature is

Phosphorus pentachloride dissociates as follows, in a closed reaction vessel: $\text{PCl}_5(g) \rightleftharpoons \text{PCl}_3(g) + \text{Cl}_2(g)$ If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of $\text{PCl}_5$ is $x$, the partial pressure of $\text{PCl}_3$ will be

For the following three reactions (i), (ii) and (iii), equilibrium constants are given: (i) $\text{CO}(g) + \text{H}_2\text{O}(g) \rightleftharpoons \text{CO}_2(g) + \text{H}_2(g); K_1$ (ii) $\text{CH}_4(g) + \text{H}_2\text{O}(g) \rightleftharpoons \text{CO}(g) + 3\text{H}_2(g); K_2$ (iii) $\text{CH}_4(g) + 2\text{H}_2\text{O}(g) \rightleftharpoons \text{CO}_2(g) + 4\text{H}_2(g); K_3$ Which of the following is correct?

Let the solubility of an aqueous solution of $\text{Mg(OH)}_2$ be $x$, then its $K_{sp}$ is

Which one of the following statements is not true?

When rain is accompanied by a thunderstorm, the collected rain water will have a pH value

For the reaction $\text{CO}(g) + \text{Cl}_2(g) \rightleftharpoons \text{COCl}_2(g)$ the $K_p / K_c$ is equal to

For the reaction: $2\text{NO}_2(g) \rightleftharpoons 2\text{NO}(g) + \text{O}_2(g)$ $(K_c = 1.8 \times 10^{-6} \text{ at } 184^\circ\text{C})$ $[R = 0.0831\text{ kJ}/(\text{mol. K})]$ When $K_p$ and $K_c$ are compared at $184^\circ\text{C}$, it is found that

An amount of solid $\text{NH}_4\text{HS}$ is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm pressure. Ammonium hydrogen sulphide decomposes to yield $\text{NH}_3$ and $\text{H}_2\text{S}$ gases in the flask. When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm? The equilibrium constant for $\text{NH}_4\text{HS}$ decomposition at this temperature is

The $\text{pK}_a$ of a weak acid (HA) is 4.5. The pOH of an aqueous buffer solution of HA in which 50% of the acid is ionized is

The equilibrium constants $K_{P1}$ and $K_{P2}$ for the reactions $X \rightleftharpoons 2Y$ and $Z \rightleftharpoons P + Q$, respectively are in the ratio of $1 : 9$. If the degree of dissociation of X and Z be equal, then the ratio of total pressures at these equilibria is

$1\ \text{M NaCl}$ and $1\ \text{M HCl}$ are present in an aqueous solution. The solution is

Species acting as both Bronsted acid and base is

Change in volume of the system does not alter which of the following equilibria?

For the reaction $\text{CO}(g) + (1/2)\text{O}_2(g) \rightleftharpoons \text{CO}_2(g)$, $K_p / K_c$ is

For the reaction equilibrium $\text{N}_2\text{O}_4(g) \rightleftharpoons 2\text{NO}_2(g)$, the concentrations of $\text{N}_2\text{O}_4$ and $\text{NO}_2$ at equilibrium are $4.8 \times 10^{-2}$ and $1.2 \times 10^{-2}\text{ mol L}^{-1}$ respectively. The value of $K_c$ for the reaction is

Consider the reaction equilibrium $2\text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{SO}_3(g)$; $\Delta H^\circ = -198\text{ kJ}$. On the basis of Le Chatelier's principle, the condition favourable for the forward reaction is

The conjugate base of $\text{H}_2\text{PO}_4^-$ is

What is the equilibrium expression for the reaction $\text{P}_4(s) + 5\text{O}_2(g) \rightleftharpoons \text{P}_4\text{O}_{10}(s)$?

The solubility product of a salt having general formula $\text{MX}_2$, in water, is $4 \times 10^{-12}$. The concentration of $\text{M}^{2+}$ ions in the aqueous solution of the salt is

The exothermic formation of $\text{ClF}_3$ is represented by the equation: $\text{Cl}_2(g) + 3\text{F}_2(g) \rightleftharpoons 2\text{ClF}_3(g);\ \Delta H = -329\text{ kJ}$ Which of the following will increase the quantity of $\text{ClF}_3$ in an equilibrium mixture of $\text{Cl}_2$, $\text{F}_2$ and $\text{ClF}_3$?

Hydrogen ion concentration in mol/L in a solution of pH = 5.4 will be :

What is the conjugate base of $\text{OH}^-$?

The equilibrium constant for the reaction $\text{SO}_3(g) \rightleftharpoons \text{SO}_2(g) + \dfrac{1}{2}\text{O}_2(g)$ is $K_c = 4.9 \times 10^{-2}$. The value of $K_c$ for the reaction $2\text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{SO}_3(g)$ will be

The first and second dissociation constants of an acid $\text{H}_2\text{A}$ are $1.0 \times 10^{-5}$ and $5.0 \times 10^{-10}$ respectively. The overall dissociation constant of the acid will be

A system is taken from state $a$ to state $c$ by two paths $adc$ and $abc$ as shown in the figure. The internal energy at $a$ is $U_a = 10\ \text{J}$. Along the path $adc$ the amount of heat absorbed $dQ_1 = 50\ \text{J}$ and the work obtained $dW_1 = 20\ \text{J}$, whereas along the path $abc$ the heat absorbed $dQ_2 = 36\ \text{J}$. The amount of work along the path $abc$ is:

A gas is taken through the cycle $A \to B \to C \to A$, as shown. What is the net work done by the gas?