What is the volume occupied by 16 g methane gas at STP?

The $$\left[\mathrm{OH}^{-}\right]$$ in a solution is $$1 \times 10^{-12} \mathrm{~mol} \mathrm{~dm}{ }^{-3}$$. What is the concentration of $$\mathrm{H}^{+}$$ ions?

Which among the following statements is true for Galvanic cell?

Identify the product $$(\mathrm{X})$$ formed in the following reaction.

$$\mathrm{C}_6 \mathrm{H}_5 \mathrm{OH}+\mathrm{CH}_3 \mathrm{COOH} \stackrel{\mathrm{H}+}{\rightleftharpoons} \mathrm{X} $$