Which of the following is not a fat-soluble vitamin?

The value of $\lambda$ with $|\lambda| < 16$ such that $2 x^2 - 10 x y + 12 y^2 + 5 x + \lambda y - 3 = 0$ represents a pair of straight lines,is

$5.6 \, \text{liter}$ of helium gas at $STP$ is adiabatically compressed to $0.7 \, \text{liter}$. Taking the initial temperature to be $T_1$,the work done in the process is

The equation of the line passing through the point of intersection of the lines $x-3y+2=0$ and $2x+5y-7=0$ and perpendicular to the line $3x+2y+5=0$ is:

Assign $A, B, C, D$ from the given type of reaction.
$HgI_2 \downarrow + 2KI \rightleftharpoons K_2[HgI_4]$

What product is obtained when ethyl hydrogen sulphate is heated with an excess of alcohol at $410 \, K$?