The catalyst used in the lead chamber process of sulphuric acid manufacture is

Observe the following reactions:
$P_4 + 8SOCl_2 \longrightarrow 4PCl_3 + 4SO_2 + 2S_2Cl_2$
$P_4 + 10SO_2Cl_2 \longrightarrow 4PCl_5 + 10SO_2$
In both the reactions,a common product '$x$' is obtained. The number of lone pair of electrons on the central atom of '$x$' is:

Which of the following is the structure of oleum?

Which of the following dissociates to give ${H^{+}}$ most easily?

What is the atomicity of sulfur in rhombic sulfur?

An amorphous solid $'A'$ burns in air to form a gas $'B'$ which turns lime water milky. The gas is also produced as a by-product during roasting of sulphide ore. This gas decolourises acidified aqueous $KMnO_4$ solution and reduces $Fe^{3+}$ to $Fe^{2+}$. Identify the solid $'A'$ and the gas $'B'$ and write the reactions involved.