The first ionization constant of H₂S is 9.1 × 10^–8. The concentration of HS^– ion in its 0.1 M solution will be:

1.	12.3 × 10–7 M	2.	11.4 × 10–6 M
3.	3.5 × 10–4 M	4.	9.54 × 10–5 M

The ionization constant of acetic acid is \(1.74 × 10^{–5}.\) The pH of acetic acid in its 0.05 M solution will be:
1. 7.81

(a) Human muscle-fluid,  pH = 6.83 

(b) Human stomach fluid, pH = 1.2

(c) Human blood, pH = 7.38           

(d) Human saliva, pH = 6.4.

The pH values of milk, tomato juice, lemon juice, and egg are 6.8, 4.2, 2.2, and 7.8 respectively.

The corresponding hydrogen ion concentration is maximum in: 

The ionization constant of propanoic acid is 1.32 × 10^–5. The degree of ionization of 0.05M acid solution will be:

1. $\mathrm{\alpha }$ = 0.63 × 10^–2

2. $\mathrm{\alpha }$ = 1.63 × 10^–4

3. $\mathrm{\alpha }$ = 1.63 × 10^–2

4. $\mathrm{\alpha }$ = 0.05 × 10^–2

The salt that gives a neutral solution in water is: 

The ionization constant of benzoic acid is 6.46×10⁵ and K_sp for silver benzoate is 2.5×10^–13. Silver benzoate is x times more soluble in a buffer of pH 3.19 compared to its solubility in pure water. The value of x will be:

1. 6.8 

2. 16.8 

3. 33.3 

4.  3.3 

Consider the following reaction:
\(\mathrm{Cu}\left(\mathrm{NO}_3\right)_2(\mathrm{~s}) \rightleftharpoons 2 \mathrm{CuO}(\mathrm{~s})+4 \mathrm{NO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g})\)

What is the equilibrium constant \(K_c\)​ expression for the above reaction?

$1. {\mathrm{K}}_{\mathrm{C}}= \frac{{\left[{\mathrm{NO}}_2\right]}^4\left[{\mathrm{O}}_2\right]}{\left[\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\right]}$
$2. {\mathrm{K}}_{\mathrm{C}}= {\left[{\mathrm{NO}}_2\right]}^4\left[{\mathrm{O}}_2\right]$
$3. {\mathrm{K}}_{\mathrm{C}} =\frac{{\left[\mathrm{CuO}\right]}^2{\left[{\mathrm{NO}}_2\right]}^4\left[{\mathrm{O}}_2\right]}{\left[\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\right]}$
$4. {\mathrm{K}}_{\mathrm{C}} =\frac{{\left[{\mathrm{NO}}_2\right]}^4\left[{\mathrm{O}}_2\right]}{\left[\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\right]}$

${{\mathrm{I}}_2}_{\left(\mathrm{s}\right)}$ $+$ $5{{\mathrm{F}}_2}_{\left(\mathrm{g}\right)}$ $$ $\to 2{\mathrm{IF}}_{5\left(g\right)}$ $$

The solution that has the lowest pH is: 

(assuming 100% dissociation)