Lewis Theory

Q.

In which of the following reactions does $N{H}_3$ act as an acid ?

1. $N{H}_3$ + $H^{+}$ $⟶$ ${N{H}_4}^{+}$

2. $N{H}_3$ + Na $⟶$ $NaN{H}_2$ + $\frac{1}{2}$ $H_2$

3. $N{H}_3$ + HCl $⟶$ $N{H}_{4}Cl$

4. None of these

Q. A solution of weak acid $HA$ was titrated with base $NaOH$. The equivalent point was reached when $40mL$ of $0.1MNaOH$ has been added. Now $20mL$ of $0.1MHCl$ were added to titraded solution, the $pH$ was found to be $5.0$. What will be the $pH$ of the solution obtained by mixing $20mL$ of $0.2MNaOH$ and $20mL$ of $0.2MHA$?

Q. Which of the following species is not a Lewis acid?

1. $B{F}_3$
2. $C{u}^{2+}$
3. $N{H}_3$
4. $AlC{l}_3$

Q. Choose the Lewis acids

1. $N{H}_3$
2. ${\mathrm{FeBr}}_3$
3. ${\mathrm{AlCl}}_3$
4. ${\mathrm{OH}}^{-}$
5. ${\mathrm{BF}}_3$
6. ${\mathrm{CH}}_3{\mathrm{NH}}_2$
7. ${\mathrm{CO}}_2$
8. ${\mathrm{GaCl}}_3$

Q.

Electrophiles are

1. Lewis acids

2. Lewis base

3. Bronsted acid

4. Bronsted base

Q. Which of the following is lewis acid?

1. $N{H}_3$
2. $AlC{l}_3$
3. $P{H}_3$
4. None of the above

Q. An acid is a substance which

1. accepts a lone pair of electron(Lewis concept)
2. donate a proton ( Lowry and Bronsted concept)
3. (a) and (b) above.
4. None of the above