A 0.02 M solution of pyridinium hydrochloride has a pH of 3.44.
The ionization constant of pyridine will be:

1. $6.6$ $\times$ ${10}^{-6}$

2. $1.51$ $\hspace{0.17em}\times$ ${10}^{-9}$

^{3. $2.36$ $\times$ ${10}^{-7}$}

4. $3.43$ $\times \hspace{0.17em}{10}^{-9}$

The ionization constant of nitrous acid is 4.5 × 10^–4.  The pH of a 0.04 M sodium nitrite solution will be:

1. 2.56

2. 6.14

3. 7.96

4. 11.74

The ionization constant of chloroacetic acid is 1.35 × 10^–3. The pH of a 0.1 M acid solution will be:

The salt that gives a neutral solution in water is: 

1. KBr

2. NH₄NO₃

3. NaCN

4. Rb₂(CO₃)