In an unbiased $p-n$ junction,holes diffuse from the $p-$ region to $n-$ region because

Which one of the following reactions represents the oxidising property of $H_2O_2$?

$X$ is a non-volatile solute and $Y$ is a volatile solvent. The following vapour pressures are observed by dissolving $X$ in $Y$:
| $X / \text{mol L}^{-1}$ | $Y / \text{mm of Hg}$ |
| :--- | :--- |
| $0.10$ | $p_1$ |
| $0.25$ | $p_2$ |
| $0.01$ | $p_3$ |
The correct order of vapour pressures is:

In a pseudo first order hydrolysis of ester in water,the following results were obtained.

$t/s$	$0$	$30$	$60$	$90$
$Ester/mol\, L^{-1}$	$0.55$	$0.31$	$0.17$	$0.085$

What will be the average rate of reaction between the time interval $30$ to $60$ seconds?

The enthalpy of the reaction,$H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(g)}$ is $\Delta H_1$ and that of $H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(l)}$ is $\Delta H_2$,then:

The equation $4x^2 - 24xy + 11y^2 = 0$ represents