Law of Definite Proportions

Front

What does the law of definite proportions state?

Back

A given chemical compound always contains the same elements in the exact same proportions by mass.

Front

What is the significance of the law of definite proportions in chemistry?

Back

It ensures that a chemical compound has a consistent composition, regardless of the source or method of preparation.

Front

In the compound CO2, what is the molar mass?

Back

44.01 g/mol.

Front

How do you calculate the mass of a compound from the mass of its elements and their percentages?

Back

Use the formula: mc = 100% x me / %me.

Front

What is the atomic mass of carbon?

Back

12.01 g/mol.

Front

What is the atomic mass of oxygen?

Back

16.00 g/mol.

Front

If a compound contains 40% carbon and 60% oxygen, what is the mass ratio of carbon to oxygen?

Back

2:3.

Front

What is an example of a compound that illustrates the law of definite proportions?

Back

Water (H2O) always contains 2 hydrogen atoms and 1 oxygen atom in a 2:1 ratio.

Front

What is the difference between the law of definite proportions and the law of multiple proportions?

Back

The law of definite proportions states that a compound has a fixed composition, while the law of multiple proportions states that when elements combine, they do so in ratios of small whole numbers.

Front

What is the formula for calculating the percentage composition of an element in a compound?

Back

(mass of element in 1 mole of compound / molar mass of compound) x 100%.