The conjugate acid of ${\mathrm{NH}}_2^{-}$ is

1. ${\mathrm{NH}}_4^{+}$

2. ${\mathrm{NH}}_3$

3. ${\mathrm{NH}}_2\mathrm{OH}$

4. ${\mathrm{N}}_2{\mathrm{H}}_4$

The pH of the neutralization point of 0.1 N ammonium hydroxide with 0.1 N HCl is

1. 1

2. 6

3. 9

4. 7

The compound whose 0.1 M solution is basic is

1. Ammonium acetate

2. Ammonium sulphate

3. Sodium acetate

4. Ammonium chloride

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) ${\mathrm{BF}}_3$

(ii) ${\mathrm{H}}_2\mathrm{O}$

(iii) ${\mathrm{HSO}}_4^{-}$

(iv) ${\mathrm{SO}}_3$

1. (i) and (iii)

2. (i) and (ii)

3. (i) and (iv)

4. (iii) and (iv)

Out of ${\mathrm{Ca}}^{2+},\hspace{0.17em}{\mathrm{Al}}^{3+},\hspace{0.17em}{\mathrm{Cr}}^{3+}, {\mathrm{Mg}}^{2+}, \mathrm{and} {\mathrm{Zn}}^{2+},$ the reagents ${\mathrm{NH}}_4\mathrm{Cl}$ and aqueous ${\mathrm{NH}}_3$ will precipitate

1. ${\mathrm{Ca}}^{2+},\hspace{0.17em}{\mathrm{Al}}^{3+}$

2. ${\mathrm{Al}}^{3+}, {\mathrm{Cr}}^{3+}$

3. ${\mathrm{Bi}}^{3+}, {\mathrm{Mg}}^{2+}$

4. ${\mathrm{Mg}}^{2+}, {\mathrm{Zn}}^{2+}$

Which among the following is the least soluble?

1. $\mathrm{MnS} ({\mathrm{K}}_{\mathrm{sp}}=7\times {10}^{-16})$

2. $\mathrm{FeS} ({\mathrm{K}}_{\mathrm{sp}}=4\times {10}^{-19})$

3. $\mathrm{PtS} ({\mathrm{K}}_{\mathrm{sp}}=8\times {10}^{-73})$

4. $\mathrm{NiS} ({\mathrm{K}}_{\mathrm{sp}}=3\times {10}^{-12})$