Question

Tell if the following (marked with * belongs to the categories below) Law of conservation of mass/ law of definite proportions/ law of multiple proportions.

* When 3g of carbon reacts with 8 g of oxygen, 11g of carbon dioxide is produced.

*The C:O mass ratio of a particular compound is the same, regardless of the size or source of the sample.

*the C:O mass ratio of one compound is exactly double that of another compound.

*Burning 10g of propane produces twice as much carbon dioxide as burning 5g of propane.

Answer 1

i)

The answer is Law of conservation of mass.

This is because, The Law of Conservation of Mass states that matter can be changed from one form into another, but the total amount of mass remains constant.

Here, the mass of reactants = mass of carbon + mass of oxygen = 3g + 8g = 11g

Mass of the products = mass of carbondioxide = 11g

Thus, as the mass of reactants = mass of products, it means that the amount of mass remains constant.

Hence, Law of conservation of mass.

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ii)

The answer is Law of multiple proportions.

This is because, The law of multiple proportions states that, If two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers.

Thus, in one compound if the C:O ratio is 1:1, in another conpound the ratio of C:O is 1:2.

Hence, this is law of multiple proportions.

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iii)

The answer is Law of definite proportions.

This is because, the law of definite proportions states that, all samples of a given chemical compound have the same elemental composition by mass.

Thus, if 2 g of propane has some ratio, then 1 g of propane also has the same ratio, but half the amount.

Thus, it is Law of definite proportions.