2 16 g of copper metal when treated with nitric acid followed by ignition of the nitrate gave 2 70 - Chemistry - Some Basic Concepts of Chemistry

Question

2 16 g of copper metal when treated with nitric acid followed by
ignition of the nitrate gave 2 70 g of copper oxide In another
experiment 1 15 g of copper oxide upon reduction with hydrogen gave
0 92 g of copper Show that the above data illustrate the law of
definite proportions

Arti Gujrati · Accepted Answer

Experiment-1
The balanced chemical reaction for this process can be written
as
Cu + 4HNO3
â†’Cu(NO3)2 +
2NO2 + H2O
2Cu(NO3)2 â†’2CuO +
4NO2 + O2
From above 2 equation it is clear that one mole of Cu will
produce one mole of CuO as end product That is 63g (atomic wt of
Cu)of Cu will produce 79g (mol wt of CuO=79) of CuO The ratio of
CuO/Cu = 79/63 =1 25
Ratio of CuO/Cu according to experimental condition = 2 7/2 16 =
1 25
Experiment-2
CuO + H2 â†’ Cu + H2
79g 63g
CuO/Cu = 79/63 = 1 25
Ratio of CuO/Cu by experimental data = 1 15/0 92 = 1 25
so in each case ratio of CuO/Cu is 1 25 that is definite this
verify law of definite proportion

2.16 g of copper metal when treated with nitric acid followed by ignition of the nitrate gave 2.70 g of copper oxide. In another experiment 1.15 g of copper oxide upon reduction with hydrogen gave 0.92 g of copper.Show that the above data illustrate the law of definite proportions.