Question

The % of Copper and Oxygen in samples of CuO obtained by different methods were found to be the same.

This proves the law of:

• A. constant proportions
• B. reciprocal proportions
• C. multiple proportions
• D. conservation of mass.

Answer 1

The correct option is A constant proportions

According to the law of constant proportions, a chemical compound always contains the same elements combined together in the same proportion by mass.

In CuO, copper and oxygen always combine in the same proportion, irrespective of the source or method of preparation.

So, the correct option is A.