A weak acid, HA, has a K_a of 1.00×10^-5. If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to:

1. 99.0%

2. 1%

3. 99.9%

4. 0.100%

The following equilibrium constants are given: 
N₂ + 3H₂ ⇌ 2NH₃; K₁ 
N₂ + O₂ ⇌ 2NO; K₂ 
H₂ + 1/2O₂ ⇌ H₂O; K₃ 

The equilibrium constant for the oxidation of NH₃ by oxygen to give NO is:

1. $K_2{K}_3^3/K_1$

2. $K_2{K}_3^2/K_1$

3. $K_2^2{K}_3/K_1$

4. $K_1{K}_2/K_3$ 

The ionic species that has the greatest proton affinity to form stable compound is:

1. $H{S}^{-}$

2. $N{H}_2^{-}$

3. $F^{-}$

4. $l^{-}$

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

1. $HOCl<HOClO<HOCl{O}_2<HOCl{O}_3$

2. $HOClO<HOCl<HOCl{O}_3<HOCl{O}_2$

3. $HOCl{O}_2<HOCl{O}_3<HOClO<HOCl$

4. $HOCl{O}_3<HOCl{O}_2<HOClO<HOCl$

For the reaction, 
CH₄(g) + 2O₂(g) CO₂(g) + 2H₂O(l) 
Δ_rH = -170.8 kJ mol^-1 
Which of the following statements is not true?
 

The following pair constitutes a buffer is:

1. $HN{O}_2$ $and$ $NaN{O}_2$

2. $NaOH$ $and$ $NaCl$

3. $HN{O}_3$ $and$ $N{H}_{4}N{O}_3$

4. $HCl$ $and$ $KCl$

The hydrogen ion concentration of a 10^-8 M HCl aqueous solution at 298 K (K_w = 10^-14) is:

1. $1.0\times {10}^{-6}$ $M$

2. $1.0525\times {10}^{-7}$ $M$

3. $9.525\times {10}^{-8}$ $M$

4. $1.0\times {10}^{-8}$ $M$

The pOH of a solution at 25 °C that contains 1×10^-10 M of hydronium ions is:

The value of the equilibrium constant of the reaction 
 $\mathrm{HI}\left(\mathrm{g}\right)$ $\leftrightharpoons$ $\frac{1}{2}{\mathrm{H}}_2\left(\mathrm{g}\right)$ $+$ $\frac{1}{2}{\mathrm{I}}_2$ is 8.0.
The equilibrium constant of the reaction
 ${\mathrm{H}}_2\left(\mathrm{g}\right)$ $+$ ${\mathrm{I}}_2\left(\mathrm{g}\right)$ $\leftrightharpoons$ $2\mathrm{HI}\left(\mathrm{g}\right)\hspace{0.17em}$ will be-

The value of K_P1 and K_p2 for the reactions
 $X$ $\leftrightharpoons$ $Y$ $+Z$ $......\left(i\right)$
$and$ $A$ $\leftrightharpoons 2B$ $......\left(ii\right)\hspace{0.17em}$
are in the ratio of 9 : 1. If the degree of dissociation of X and A is equal, then the total pressure at equilibrium(i) and (ii) are in the ratio: