Law of Constant Proportions

IMPORTANT

Important Questions on Law of Constant Proportions

MEDIUM
IMPORTANT

0.24g sample of a compound of oxygen and boron was found by analysis to contain 0.144g of oxygen and 0.096g of boron. Calculate the percentage composition of the compound by weight. 

EASY
IMPORTANT

For all the molecules of water to be identical, it is essential that the atoms of hydrogen and oxygen that are present in the molecule must be in fixed numbers. If this number is not fixed, how could all the particles of water be identical? 

EASY
IMPORTANT

Is it possible for any number of atoms of hydrogen to combine with any number of atoms of oxygen to form a molecule of water? 

EASY
IMPORTANT

Discuss if the carbon dioxide that you breathe out and the carbon dioxide others breathe out is identical. Is the composition of the carbon dioxide of different sources the same? 

HARD
IMPORTANT

100g of mercuric oxide decomposes to give 92.6g of mercury and 7.4g of oxygen. Let us assume that 10g of oxygen reacts completely with 125g of mercury to give mercuric oxide. Do these values agree with the law of constant proportions? 

MEDIUM
IMPORTANT

Proust took two samples of copper carbonate - a compound of copper, carbon and oxygen. He took a sample from nature and another sample prepared in the lab and decomposed it chemically to find the percentage of copper, carbon and oxygen in the two samples. The results obtained are given in the following table.

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What difference do you observe in the percentage of copper, carbon and oxygen in the two samples? 

EASY
IMPORTANT

Proust took two samples of copper carbonate - a compound of copper, carbon and oxygen. He took a sample from nature and another sample prepared in the lab and decomposed it chemically to find the percentage of copper, carbon and oxygen in the two samples. The results obtained are given in the following table.

Question Image

What do you observe from the table?