Question

Which of the following gives nitrogen dioxide on reacting with concentrated nitric acid?
Pb
Ca
Al
K

Answer 1

Answer:

'Ca' reacts with concentrated nitric acid to give nitrogen dioxide.

Explanation:

When calcium is reacted with concentrated nitric acid, the reaction is as follows:

Ca(s) + HNO3(aq) = Ca(NO3)2(aq) + NO2(g) + H2O(l)

If the concentration of nitric acid is considerably high, it behaves as an oxidizing acid. Then, the products are : calcium nitrate, nitrogen dioxide and water.

The color of nitrogen gas which is released after the reaction is brown.

Answer 2

Answer:

Pb is the correct answer

Explanation:

Pb+HNO³ -> Pb(NO³)²+ NO² + H²O