What are the products formed when chlorine is passed through an aqueous hypo solution?

$A$ car is moving with a speed of $72 ~km/h$ towards a hill. The car blows its horn at a distance of $1800 ~m$ from the hill. If the echo is heard after $10 ~s$,what is the speed of sound in $m/s$?

$\frac{d}{d x} \sin ^{-1}\left(3 x-4 x^3\right)$ is equal to

The distance between two coherent sources is $0.1 \, mm$. The fringe-width on a screen $1.2 \, m$ away from the source is $6.0 \, mm$. The wavelength of light used is $\dots \, \mathring{A}$.

If $|x| < 1$ and $y = x - \frac{x^2}{2} + \frac{x^3}{3} - \frac{x^4}{4} + \ldots$,then $x$ is equal to :

$\lim _{x \rightarrow 0} \frac{\sin x \sin ^{-1} x}{x^2}$ is equal to