Which blue-colored liquid is obtained upon reacting equimolar amounts of two gases at $-30\,^{\circ}C$?

The number of $P-OH$ bonds present in pyrophosphoric acid and hypophosphoric acid is respectively

Why is $N_2$ less reactive at room temperature?

Which of the following statements are correct about the reaction between the copper metal and dilute $HNO_3$?
$(I)$ The principal reducing product is $NO$ gas.
$(II)$ $Cu$ metal is oxidised to $Cu^{2+}$ (aq.) ion which is blue in colour.
$(III)$ $NO$ is paramagnetic and has one unpaired electron in antibonding molecular orbital.
$(IV)$ $NO$ reacts with $O_2$ to produce $NO_2$ which is linear in shape.
Choose the correct statements.

Calcium phosphide reacts with water to form $Ca(OH)_2$ and $X$. When $X$ is passed into $CuSO_4$ solution,$Y$ and $H_2SO_4$ are formed. What is $Y$?

Which of the following combinations does not liberate $NH_3$ gas?