Question

1.179 g of copper on heating in air gave 1.476 g of a black oxide of copper (||). 1.375 g of black copper(||) oxide on reduction with hydrogen gave 1.098 g of copper. Show that these results illustrate the law of constant proportions​

Answer 1

Answer:

2.42 gms of copper gives 3.025 gms of black oxide(CuO)

=> percentage of copper in cuo = 2.42/3.025  x 100 = 80%

=> percentage of oxygen in cuo = 100 - 80 = 20 %

Ratio of copper : oxygen = 80 : 20 = 4:1

Similarly ,

6.49 gms of black oxide gave 5.192 gm of copper

=> Percentage of copper in cuo = 5.192/6.49  x 100 = 80 %

percentage of oxygen in cuo = 100 - 80 = 20 %

Ratio of copper : oxygen = 80 : 20 = 4:1

Hence in both the reactions the ratio of copper : oxygen is same

Hence these figures are in accordance with law of constant proportion