The oxidation state of the central atom in the anion of the compound ${\mathrm{NaH}}_2{\mathrm{PO}}_2$ will be-

1. +3

2. +5

3. +1

4. -3

Which of the following is not tetrahedral in shape?

$1.<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>{\mathrm{NH}}_4^{+}$
$2.<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>{\mathrm{SiCl}}_4$
$3.<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>{\mathrm{SF}}_4$
$4.<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>{\mathrm{SO}}_4^{2-}$

Which of the following are peroxoacids of sulphur?

Hot conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ acts as moderately strong oxidising agent. It oxidises both metals and non-metals. Which of the following element is oxidised by conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ into two gaseous products?

A black compound of manganese reacts with a halogen acid to give greenish-yellow gas. When an excess of this gas reacts with ${\mathrm{NH}}_3$ an unstable trihalide is formed. In this process, the oxidation state of nitrogen changes from-

1. –3 to +3

2. –3 to 0

3. –3 to +5

4. 0 to –3

In the preparation of compounds of Xe, Bartlett had taken ${\mathrm{O}}_2^{+}{\mathrm{PtF}}_6^{-}$ as a base compound. This is because:

In solid-state, PCl₅ exists as: 

Reduction potentials of some ions are given below. Arrange them in decreasing order of oxidising power.

If chlorine gas is passed through a hot NaOH solution, two changes are observed in the oxidation number of chlorine during the reaction. These are ......... and  .............

a. 0 to +5

b. 0 to +3

c. 0 to -1

d. 0 to +1

Choose the correct option:

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, c)

Which of the following is correct for P₄ molecule of white phosphorus?

a. It has 6 lone pairs of electrons

b. It has six P — P single bonds

c. It has three P — P single bonds

d. It has four lone pairs of electrons

Choose the correct option:

1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)