The flocculation value of $\mathrm{H}\mathrm{C}\mathrm{l}$ for arsenic sulphide sol is $30\mathrm{m}\mathrm{m}\mathrm{o}\mathrm{l}{\mathrm{L}}^{-1}$ . If ${\mathrm{H}}_2{\mathrm{S}\mathrm{O}}_4$ is used for the flocculation of arsenic sulphide, the amount, in grams of ${\mathrm{H}}_2{\mathrm{S}\mathrm{O}}_4$ in $250\mathrm{m}\mathrm{L}$ required for the above purpose is (Molecular mass of ${\mathrm{H}}_2{\mathrm{S}\mathrm{O}}_4=98\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$  )                 

At 25°C the standard emf of cell having reactions involving two electrons change is found to be 0.295 V. The equilibrium constant of the reaction is :

Kindly consider the following 

Which of the following will not give ether as product :-

Which is most reactive towards electrophilic aromatic substitution reaction :-

Which one of the following ions is the most stable in aqueous solution ?

(At. No. Ti = 22, V = 23, Cr = 24, Mn=25)