The concentration of CH₃COOH that will have the same [H⁺] as obtained from 10^-2 M HCOOH, is: 

$\left(\mathrm{Ka}\right({\mathrm{CH}}_3\mathrm{COOH})={10}^{-5},$ $\mathrm{Ka}\left(\mathrm{HCOOH}\right)={10}^{-4})$

1. 10 M

2. 5 M

3. 10^-1 M

4. 6 M

What happens when NH₄Cl is added to an aqueous solution of NH₄OH?

1. Concentration of $\left[{\mathrm{OH}}^{-}\right]$ ions decreases.

2. Concentration of $\left[{\mathrm{OH}}^{-}\right]$ ions increases.

3. Concentration of $\left[{\mathrm{NH}}_4^{+}\right]$ ions as well as concentration $\left[{\mathrm{OH}}^{-}\right]$ ions increase.

4. Concentration of $\left[{\mathrm{NH}}_4^{+}\right]$ ions decreases.

A solution of benzoic acid (a weak monobasic acid) is titrated with NaOH. The pH of the solution is 4.2 when half of the acid is neutralized. The dissociation constant of the acid will be:

1. $3.2\times {10}^{-5}$

2. $6.42\times {10}^{-4}$

3. $6.31\times {10}^{-5}$

4. $8.7\times {10}^{-8}$

The mixture that shows the maximum buffer capacity is:

The pH of a solution containing 0.1 mol of CH₃COOH, 0.2 mol of CH₃COONa, and 0.05 mol of NaOH in 1 L of solution is-

(pK_a of CH₃COOH=4.74 and log 5=0.7)

1. 4.56

2. 5.44

3. 5.04

4. 3.74

Which of the following is an amphiprotic (can accept and give protons) ion?

1. ${\mathrm{HPO}}_3^{-}$

2. ${\mathrm{H}}_2{\mathrm{PO}}_2^{-}$

3. ${\mathrm{H}}_3{\mathrm{PO}}_4$

4. ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$

Find the pH of a buffer prepared by mixing 10 mL of 1.0 M CH₃COOH with 20 mL of 0.5 M CH₃COONa and diluting the mixture to 100 mL with distilled water. Given:

pKₐ(CH₃COOH) = 4.76

1. 5.21

2. 4.76

3. 4.34

4. 5.35

The self-ionization constant for pure formic acid, K = [\(H C O O H_{2}^{+} \left]\right. \left[\right. H C O O^{-} \left]\right.\) ] has been estimated as \(\left(10\right)^{- 4}\) at room temperature. The percentage of formic acid molecules in pure formic acid that are converted to formate ions is

\(\left(\right. Given : d_{HCOOH} = 1 . 22\ g / cc \left.\right)\)

1. 0.0185%

2. 0.0073%

3. 0.074%

4. 0.037%

When 0.1 mol of CH₃NH₂ $({\mathrm{K}}_{\mathrm{b}}=5\times {10}^{-4})$ is mixed with 0.08 mol of HCl and diluted to 1 L, the H⁺ ion concentration in the solution will be :

1. $8\times {10}^{-11}$ $\mathrm{M}$

2. $6\times {10}^{-5}$ $\mathrm{M}$

3. $1.6\times {10}^{-11}$ $\mathrm{M}$

4. $8\times {10}^{-2}$ $\mathrm{M}$

The molecule that cannot function as both Bronsted acid and base: 

1. ${\mathrm{HCO}}_3^{-}$

2. ${\mathrm{NH}}_3$

3. HCl

4. ${\mathrm{HSO}}_4^{-}$