Question

7.95 gram of copper oxide was reduced by heating in a current of hydrogen and weight of copper that remained is 6.35 grams in another experiment 19.05 gram of copper was dissolved in nitric acid and the resulting copper nitrate is converted into the cupric acid by ignition the weight of cupric acid form was 23.8 5 gram show this is in the respect of law of constant proportion in another experiment 19.05 gram of copper was dissolved in nitric acid and the resulting copper nitrate is converted into the cupric acid by ignition the weight of cupric acid form was 23.8 5 gram show this is in the respect of law of constant proportion

Answer 1

Answer:

ANSWER

First experiment

∙ Copper oxide =1.375g

∙ Copper left =1.098g

∙ Oxygen present =1.375−1.098=0.277g

Percentage of oxygen in CuO=(0.277)(100 %) 1.375=20.15 %

Second Experiment

∙ Copper taken =1.179g

∙ Copper oxide formed =1.476g

∙ Oxygen present =1.476−1.179=0.297g

Percentage of oxygen in CuO=(0.297)(100 %) 1.476=20.12 %

Percentage of oxygen is approximately (within significant figures limit) the same in both the above cases. So the law of constant composition is illustrated.

In chemistry, the law of definite proportion, sometimes called Proust's law or the law of definite composition, or law of constant composition states that a given chemical compound always contains its component elements in fixed ratio and does not depend on its source and method of preparation.