When 0.1 mole of CH₃NH₂ (ionization constant ${\mathrm{K}}_{\mathrm{b}}=5\times {10}^{-4}$) is mixed with 0.08 mol HCl and the volume is made up of 1 litre. The [H⁺] of resulting solution is -

(log 4 =  0.60)

1. $8\times {10}^{-2}$

2. $2\times {10}^{-11}$

3. $1.23\times {10}^{-4}$

4. $8\times {10}^{-11}$

The solution with pH value close to 1.0 among the following is:

If ${\mathrm{Ag}}^{+}+2{\mathrm{NH}}_3\rightleftharpoons \mathrm{Ag}{{\left({\mathrm{NH}}_3\right)}_2}^{+}; {\mathrm{K}}_1=1.8\times {10}^7$

${\mathrm{Ag}}^{+}+{\mathrm{Cl}}^{-}\rightleftharpoons \mathrm{AgCl}; {\mathrm{K}}_2=5.6\times {10}^9$

Then for

$\mathrm{AgCl}+2{\mathrm{NH}}_3\rightleftharpoons {\left[\mathrm{Ag}{\left({\mathrm{NH}}_3\right)}_2\right]}^{+}+{\mathrm{Cl}}^{-},$

Equilibrium constant will be

1. $0.32\times {10}^{-2}$

2. $3.11\times {10}^2$

2. $10.08\times {10}^{16}$

4. $1.00\times {10}^{-17}$

Three sparingly soluble salts A₂X, AX, and AX₃ have the same solubility product. Their solubilities will be in the order:

1. AX₃>AX>A₂X

2. AX₃ < A₂X>AX

3. AX>AX₃>A₂X

4. AX>A₂X>AX₃

Which of the following solution(s) have pH between 6 and 7?

I. $2\times {10}^{-6} \mathrm{M}\hspace{0.17em}\mathrm{NaOH}$

II. $2\times {10}^{-6} \mathrm{M}\hspace{0.17em}\mathrm{HCL}$

III. ${10}^{-8} \mathrm{M}\hspace{0.17em}\mathrm{HCl}$

IV. ${10}^{-13} \mathrm{M}\hspace{0.17em}\mathrm{NaOH}$

1. I, II

2. II, III

3. III, IV

4. II, III, IV

At what pH does Mg(OH)₂ start to precipitate from a solution with 0.10 M Mg²⁺ ions, given that the Ksp of Mg(OH)₂ is 1 × 10⁻¹¹?

1. 3

2. 6

3. 9

4. 11

50 litres of 0.1 M HCl are mixed with 50 litres of 0.2 M NaOH. The pH of the resulting solution will be:

1. 12.70

2. 12.34

3. 8.7

4. 4.2

The pH of a 0.05 M aqueous solution of diethylamine is 12. Its K_b value will be:

1. $2\times {10}^{-3}$

2. $2.5\times {10}^{-3}$

3. $3\times {10}^{-3}$

4. $4.5\times {10}^{-3}$

K_a for HCN is $5\times {10}^{-10}$ at $25°\mathrm{C}$. For maintaining a constant pH of 9, the volume of 5 M KCN solution required to be added to 10 mL of 2 M HCN solution is-

1. 2 mL

2. 3 mL

3. 4.2 mL

4. 5.6 mL

The approximate pH of a solution formed by mixing equal volumes of solutions of 0.1 M sodium propionate and 0.1 M propanoic acid (the dissociation constant of propanoic acid is $1.3\times {10}^{-5} \mathrm{mol} {\mathrm{dm}}^{-3}$) will be

1. 2.45

2. 4.89

3. 5.98

4. 6.89