The pH value of a 0.01 M solution of an organic acid is 4.15. The pK_a of the acid will be:

$1.$ $8.95$
$2.$ $1.43$
$3.$ $3.56$
$4.$ $6.30$

A 0.001 M aniline solution has a pH of:
(\(K_b = 4.27 \times 10^{-10}\))

The degree of ionization of 0.05 M acetic acid is:

(pK_a = 4.74 )

$1.$ $1.91$ $\times {10}^{-2}$
$2.$ $2.46$ $\times$ ${10}^2$
$3.$ $1.93$ $\times$ ${10}^2$
$4.$ $2.34$ $\times$ ${10}^{-3}$

The percentage ionization of 0.02 M dimethylamine solution if it also contains 0.1 M NaOH solution (K_b of dimethylamine = 5.4 × 10^–4 ) will be :

1. 0.54%

2. 0.05%

3. 5.40%

4. 54.00%

The pH of a 0.1 M solution of cyanic acid (HCNO) is 2.34. The ionization constant of the acid will be:

$1.$ $2.02$ $\times$ ${10}^4$
$2.$ $3.14$ $\times$ ${10}^3$
$3.$ $2.02$ $\times$ ${10}^{-4}$
$4.$ $1.01$ $\times$ ${10}^{-4}$

The ionization constants of  HCOOH, and HCN at 298K are  1.8 × 10^–4 and 4.8 × 10^–9 respectively. The ionization constants of the corresponding conjugate bases of HCOOH and HCN will be:

1. 5.6 x 10^-11, 2.08 x 10^-6

2. 2.4 x 10^-11, 4.2 x 10^-6

3. 3.5 x 10^-11, 1.7 x 10^-6

4. 4.2 x 10^-11, 1.2 x 10^-6

The ionization constant of phenol is 1.0 × 10^–10. The concentration of phenolate ion in 0.05 M solution of phenol will be -

1. 4.2 x 10^-4 M

2. 3.6 x 10^-5 M

3. 7.8 x 10^-6 M

4. 2.2 x 10^-6 M

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

The ionization constant of acetic acid is 1.74 × 10^–5. The pH of acetic acid in its 0.05 M solution will be:

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 x 10^-2

2. $\mathrm{\alpha }$ = 1.63 x 10^-4

3. $\mathrm{\alpha }$ = 1.63 x 10^-2

4. $\mathrm{\alpha }$ = 0.05 x 10^-2