How do you find PERCENT composition by mass or PERCENT Purity calculations
To find the percent composition by mass of a compound, you would first determine the mass of each element present in the compound. Then, calculate the total mass of the compound. Finally, divide the mass of each element by the total mass and multiply by 100 to find the percent composition of each element.
For example, if you have a compound with a mass of 60g containing 40g of carbon and 20g of hydrogen, you would calculate the percent composition of carbon as follows:
(40g / 60g) x 100 = 66.67% carbon
And the percent composition of hydrogen as:
(20g / 60g) x 100 = 33.33% hydrogen
To find the percent purity of a substance, you would need to know the mass of the pure substance and the total mass of the sample. Then, divide the mass of the pure substance by the total mass of the sample and multiply by 100 to find the percent purity.
For example, if you have a sample of a substance weighing 90g and you determine that 70g of it is pure, you would calculate the percent purity as follows:
(70g / 90g) x 100 = 77.78% pure.
These calculations are commonly used in chemistry to determine the composition of compounds and the purity of substances.