Which of the following gases is insoluble in water?

Explain the laboratory preparation of dihydrogen.

Which of the following statements are $NOT$ correct?
$A$. Hydrogen is used to reduce heavy metal oxides to metals.
$B$. Heavy water is used to study reaction mechanism.
$C$. Hydrogen is used to make saturated fats from oils.
$D$. The $H-H$ bond dissociation enthalpy is lowest as compared to a single bond between two atoms of any elements.
$E$. Hydrogen reduces oxides of metals that are more active than iron.
Choose the most appropriate answer from the options given below:

The product$(s)$ of the reaction $NaBH_4 + I_2 \longrightarrow$ 'Products' is/are

What else is present in a fire extinguisher besides $H_2SO_4$?

Identify the correct statement from the following.