The catalyst and promoter respectively used in the Haber's process of industrial synthesis of ammonia are

The molar heat capacity of water at constant pressure is $75 \ J \ K^{-1} \ mol^{-1}$. When $1.0 \ kJ$ of heat is supplied to $100 \ g$ of water which is free to expand,the increase in temperature of water is ............. $K$.

Which of the following mineral elements is responsible for the permeability of the cell membrane?

If the chord of contact of tangents from a point on the circle $x^2 + y^2 = r_1^2$ to the circle $x^2 + y^2 = r_2^2$ touches the circle $x^2 + y^2 = r_3^2$,then $r_1, r_2, r_3$ are in:

In the reaction $\underset{\text{(Vapour)}}{C_2H_5OH} \xrightarrow[300^{\circ} C]{Cu} X$. The molecular formula of $X$ is

Which of the following is a synthetic auxin?