What is the total number of -OH groups present in ribonucleoside?

The rate constant of a first order reaction is $1.15 \times 10^{-3} \mathrm{~s}^{-1}$. How long will 5 g of reactant take to reduce to 3 g ?

Identify the element forming peroxide on reaction with oxygen.

Consider galvanic cell, ${ }^{\ominus} \mathrm{A}_{(\mathrm{s})}\left|\mathrm{A}_{(\mathrm{aq})}^{+2}\right|\left|\mathrm{B}_{(\mathrm{aq})}^{+}\right| \mathrm{B}_{(\mathrm{s})}^{\oplus}$

if emf of cell is positive, identify a correct cell reaction from following.