Question

In the manufacture of nitric acid by Ostwald's process,___________ as a dehydrating agent is used to convert $68\%$ by mass of $HN{O}_3$ to $98\%$ by mass of $HN{O}_3$?

Answer 1

The dehydrating agent used to increase the concentration of $HN{O}_3$ is $H_{2}S{O}_4$. $H_{2}S{O}_4$ absorbs water from $HN{O}_3$ and concentrated $HN{O}_3$ is obtained.