When $H_2SO_4$ reacts with $PCl_5$,the obtained product$(s)$ is/are:

Oxygen is not evolved on reaction of ozone with

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.

Which of the following sets of atomic numbers corresponds to elements of group $16$?

Which of the following is the strongest reducing agent?

Which of the following chemical reactions demonstrates the oxidizing nature of $H_2SO_4$?