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)?

Ca²⁺, Al³⁺, Cr³⁺, Mg²⁺, Zn²⁺

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

2. ${\mathrm{Al}}^{3+},<mspace\; width="1em"></mspace>{\mathrm{Cr}}^{3+}$

3. ${\mathrm{Bi}}^{3+},<mspace\; width="1em"></mspace>{\mathrm{Mg}}^{2+}$

4. ${\mathrm{Mg}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Zn}}^{2+}$

Which among the following is the least soluble?

1. $\mathrm{MnS}<mspace\; width="1em"></mspace>({\mathrm{K}}_{\mathrm{sp}}=7\times {10}^{-16})$

2. $\mathrm{FeS}<mspace\; width="1em"></mspace>({\mathrm{K}}_{\mathrm{sp}}=4\times {10}^{-19})$

3. $\mathrm{PtS}<mspace\; width="1em"></mspace>({\mathrm{K}}_{\mathrm{sp}}=8\times {10}^{-73})$

4. $\mathrm{NiS}<mspace\; width="1em"></mspace>({\mathrm{K}}_{\mathrm{sp}}=3\times {10}^{-12})$

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. ${\mathrm{Ka}}_2=1/{\mathrm{Ka}}_1$

For sparingly soulble salt ${\mathrm{A}}_{\mathrm{p}}{\mathrm{B}}_{\mathrm{q}}$, the relationship of its solubility product ${\mathrm{(L}}_{\mathrm{s}}$) with its solubility (s) is:

1. ${\mathrm{L}}_{\mathrm{s}}={\mathrm{s}}^{\mathrm{p}+\mathrm{q}}.{\mathrm{p}}^p.{\mathrm{q}}^{\mathrm{q}}$

2. ${\mathrm{L}}_{\mathrm{s}}={\mathrm{s}}^{\mathrm{p}+\mathrm{q}}.{\mathrm{p}}^{\mathrm{q}}.{\mathrm{q}}^{\mathrm{q}}$

3. ${\mathrm{L}}_{\mathrm{s}}={\mathrm{s}}^{\mathrm{pq}}{\mathrm{p}}^{\mathrm{q}}{\mathrm{q}}^{\mathrm{q}}$

4. ${\mathrm{L}}_{\mathrm{s}}={\mathrm{s}}^{\mathrm{pq}}.{\left(\mathrm{pq}\right)}^{\mathrm{p}+\mathrm{q}}$

Find the correct order of acid strength for acids A, B, and C having pKa values 4.3, 3.3, and 5.5, respectively.

1. A>B>C

2. C>A>B

3. B>A>C

4. C>B>A

Which of the following statements are correct?

1. II, and III
2. I, II, and III
3. III, and IV
4. II, III, and IV