Which of the following orders is correct for the heat of hydrogenation of these compounds?

$\int_{3}^{6} \frac{\sqrt{x}}{\sqrt{9-x} + \sqrt{x}} \, dx = $

Pick up the wrong statement.

The amount of heat energy required to raise the temperature of $1\, g$ of Helium at $NTP$ from $T_1\, K$ to $T_2\, K$ is

The coefficient of apparent expansion of mercury in a glass vessel is $153 \times 10^{-6}/^{\circ}C$ and in a steel vessel is $144 \times 10^{-6}/^{\circ}C$. If $\alpha$ for steel is $12 \times 10^{-6}/^{\circ}C$,then $\alpha$ for glass is:

In a food chain,the total amount of living material is depicted by