Which of the following vitamins is water-soluble?

The foci of the ellipse $\frac{x^{2}}{16}+\frac{y^{2}}{b^{2}}=1$ and the hyperbola $\frac{x^{2}}{144}-\frac{y^{2}}{81}=\frac{1}{25}$ coincide. Then the value of $b^{2}$ is:

In compound $X$,all the bond angles are exactly ${109^o}28'$,$X$ is

What is the major product of the following reaction?

The equation of the sphere passing through the points $(1,0,0)$, $(0,1,0)$, and $(1,1,1)$ and having the smallest radius is:

$A$ weak acid $HX$ has the dissociation constant $1 \times 10^{-5} \ M$. It forms a salt $NaX$ on reaction with alkali. The percentage hydrolysis of $0.1 \ M$ solution of $NaX$ is ........ $\%$.