Conjugate acid of NH₂^– is:

1. NH₄OH

2. NH₄⁺

3. \(NH_{2}^{-}\)

4. NH₃

Incorrect statement about pH and H⁺ is: 
 

At 25 ºC, the dissociation constant of a base, BOH, is 1.0 × 10^–12. The concentration of hydroxyl ions in 0.01M aqueous solution of the base would be:

$\mathrm{If\; A}$ $+$ $B$ $\leftrightharpoons$ $C$ $+$ $D$ $Cons\tan t$ $=$ $K_1$
$E$ $+$ $F$ $\rightleftharpoons$ $G$ $+$ $H$ $Cons\tan t$ $=$ $K_2$

then C + D + E + F ⇒ product. The constant of reaction will be:

1.  $\frac{K_1}{K_2}$

2.  $\frac{K_2}{K1}$

3. $K_1{K}_2$

4. None of these 

The fertilizer which makes the soil acidic is:

1. ${\left(N{H}_4\right)}_{2}S{O}_4$

2.  Super phosphate of lime .

3. $C{H}_{3}COONa$

4. $Ca{\left(N{O}_3\right)}_2$

What is the correct relationship between the pHs of isomolar solutions of sodium oxide (pH₁), sodium sulphide (pH₂), sodium selenide (pH₃), and sodium telluride (pH₄)?

1. ${\mathrm{pH}}_1<{\mathrm{pH}}_2<{\mathrm{pH}}_3<{\mathrm{pH}}_4$

2. ${\mathrm{pH}}_1>{\mathrm{pH}}_2>{\mathrm{pH}}_3>{\mathrm{pH}}_4$

3. ${\mathrm{pH}}_1<{\mathrm{pH}}_2<{\mathrm{pH}}_3\approx {\mathrm{pH}}_4$

4. ${\mathrm{pH}}_1>{\mathrm{pH}}_2\approx {\mathrm{pH}}_3>{\mathrm{pH}}_4$

H₂S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because:
 

Among the following examples, the species that behave(s) as a Lewis acid is/are: 
$B{F}_3,SnC{l}_2,SnC{l}_4$ 
1. Stannous chloride, stannic chloride
2. $B{F}_3$, stannous chloride
3. Only $B{F}_3$
4. $B{F}_3$, stannous chloride , stannic chloride

4 gm of NaOH is dissolved in 1000 ml of water. The ${\mathrm{H}}^{+}$ ion concentration will be:

The solubility product of a sparingly soluble salt AX₂ is 3.2 ×10^–11. Its solubility (in moles/litre) is:

1. 3.1×10^–4

2. 2 × 10^–4

3. 4 × 10^–4

4. 5.6 × 10^–6