equilibrium Questions

A charged oil drop is suspended in a uniform field of $3\times 10^4\text{V/m}$ so that it neither falls nor rises. The charge on the drop will be: (Take mass of the drop $=9.9\times 10^{-15}\text{kg}$ and $g=10{\text{m/s}}^2$)

The conjugate base of ${\text{H}}_2{\text{PO}}_4^{-}$ is:

What is the equilibrium expression for the reaction ${\text{P}}_4(s)+5{\text{O}}_2(g)\rightleftharpoons {\text{P}}_4{\text{O}}_{10}(s)$?

For the reaction, $\text{CO}(g)+{\text{Cl}}_2(g)\rightleftharpoons {\text{COCl}}_2(g)$ the $\frac{K_p}{K_c}$ is equal to:

The equilibrium constant for the reaction ${\text{N}}_2(g)+{\text{O}}_2(g)\rightleftharpoons 2\text{NO}(g)$ at temperature $T$ is $4\times 10^{-4}$. The value of $K_c$ for the reaction $\text{NO}(g)\rightleftharpoons \frac{1}{2}{\text{N}}_2(g)+\frac{1}{2}{\text{O}}_2(g)$ at the same temperature is:

The molar solubility product of a salt ${\text{A}}_2{\text{B}}_3$ is $K_{sp}$. The solubility '$s$ ' is given in terms of $K_{sp}$ by the relation: