If 9.3 g of phosphorus was used in the reaction, calculate : The volume of nitrogen dioxide produced at STP. [H = 1, N = 14, P = 31 ,O = 16]

Question

Concentrated nitric acid oxidises phosphorus to phosphoric acid according to the equation :

P + 5HNO3(conc.) ---> H3PO4 + H2O + 5NO2

If 9.3 g of phosphorus was used in the reaction, calculate : The volume of nitrogen dioxide produced at STP. [H = 1, N = 14, P = 31 ,O = 16]

Answer 1

From the equation :

1 mole of phosphorus liberates 5 ***** of nitrogen dioxide

0.3 mole of phosphorus liberates = 5 x 0.3

Now, at STP 1 mole of NO2 occupies 22.4 l

1.5 mole of NO2 occupies = 22.4 x 1.5 = 33.6 l