Velocity of sound waves in air is $330 \ m/s$. For a particular sound wave in air,a path difference of $40 \ cm$ is equivalent to a phase difference of $1.6 \pi$. The frequency of this wave is: (in $Hz$)

Arrange $CCl_4, AlCl_3, PCl_5$ and $SiCl_4$ in the order of their ease of hydrolysis.

$A$ small sphere oscillates simple harmonically in a watch glass whose radius of curvature is $1.6 \ m$. The period of oscillation of the sphere in seconds is (acceleration due to gravity,$g = 10 \ m/s^2$). (in $\pi$)

In the figure, a potential of $+1200 \, V$ is applied to point $A$ and point $B$ is earthed. What is the potential at point $P$ (in $V$)?

Observe the following reactions at $T(K)$:
$I. A \rightarrow \text{products}$
$II. 5Br^{-}_{(aq)} + Br{O_{3}}^{-}_{(aq)} + 6H^{+}_{(aq)} \rightarrow 3Br_{2(aq)} + 3H_{2}O_{(l)}$
Both the reactions are started at $10.00 \text{ am}$. The rates of these reactions at $10.10 \text{ am}$ are same. The value of $-\frac{\Delta[Br^{-}]}{\Delta t}$ at $10.10 \text{ am}$ is $2 \times 10^{-4} \text{ mol L}^{-1} \text{ min}^{-1}$. The concentration of $A$ at $10.10 \text{ am}$ is $10^{-1} \text{ mol L}^{-1}$. What is the first order rate constant (in $\text{min}^{-1}$) of reaction $I$?

$A$ particle of mass $M$ at rest decays into two particles of masses $m_1$ and $m_2$ having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles,$\lambda_1/\lambda_2$ is