Find the compound whose 0.1 M aqueous solution is basic.

1. Ammonium acetate, CH₃COONH₄
2. Ammonium sulphate, (NH₄)₂SO₄
3. Sodium acetate, CH₃COONa
4. Ammonium chloride, NH₄Cl

Fear or excitement, generally causes one to breathe rapidly and it results in the decrease of CO₂ concentration in blood. In what way will it change the pH of blood?

1. pH will increase

2. pH will decrease

3. no change

4. pH will adjust to 7

Which of the following combinations can be used to prepare a buffer solution?

I. Sodium acetate and acetic acid in water

II. Sodium acetate and hydrochloric acid in water

III. Ammonia and ammonium chloride in water

IV. Ammonia and sodium hydroxide in water.

1. I, III, IV

2. III, IV

3. I, II, IV

4. I,  III

The basic buffer solution among the following is: 

1. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{NH}}_4\mathrm{OH}$

2. $\mathrm{NaCl}+\mathrm{NaOH}$

3. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{CH}}_3\mathrm{COOH}$

4. ${\mathrm{CH}}_3\mathrm{COONa}+{\mathrm{CH}}_3\mathrm{COOH}$

Conjugate base of hydrazoic acid is: 

1. \({HN_3}^-\)${}_{}^{}$

2. \(N_2^-\)   ${\mathrm{}}_{}^{}$

3. \(N_3^-\) 
4. \({N^3}^-\)

Which of the following are Lewis acids?

(i) \(BF_3\)

(ii) \(H_2O\) ${\mathrm{}}_{}$

(iii) \(HSO_4^-\)${}_{}^{}$

(iv) \(SO_3\)
 

1. (i) and (iii)

2. (i) and (ii)

3. (i) and (iv)

4. (iii) and (iv)

Which of the following cations will form precipitates when treated with a mixture of ammonium chloride (NH₄Cl) and aqueous ammonia (NH₃)?
\(\mathrm{Ca}^{2+}, \mathrm{Al}^{3+}, \mathrm{Cr}^{3+}, \mathrm{Mg}^{2+}, \mathrm{Zn}^{2+} \)
1. \(\mathrm{Ca}^{2+}, \mathrm{Al}^{3+} \)
2. \(\mathrm{Al}^{3+}, \mathrm{Cr}^{3+}\)
3. \(\mathrm{Bi}^{3+}, \mathrm{Mg}^{2+}\)
4. \(\mathrm{Mg}^{2+}, \mathrm{Zn}^{2+}\)

Find the least soluble salt among the following.

The dissociation constant of a substituted benzoic acid at $25°\mathrm{C}$ is $1\times {10}^{-4}.$ The pH of a 0.01 M solution of its sodium salt of benzoic acid is:

Which one of the following is true for any diprotic acid, ${\mathrm{H}}_2\mathrm{X}$?

1. ${\mathrm{Ka}}_1={\mathrm{Ka}}_2$

2. ${\mathrm{Ka}}_2>{\mathrm{Ka}}_1$

3. ${\mathrm{Ka}}_1>{\mathrm{Ka}}_2$

4. ${\mathrm{Ka}}_2=1/{\mathrm{Ka}}_1$