Question

to determine percent composition from a chemical formula, you assume you have 1 mol of a compound and calculate its molar mass. determine the mass of each element by multiplying its molar mass by its in the chemical formula. then divide by the of the compound and multiply by 100.

Answer 1

To find the percent composition of a compound, calculate the molar mass of the compound, determine mass of each element based on its atomic mass and subscript in the formula, divide by the compound's molar mass and multiply by 100%.

Step-by-step explanation:

To calculate the percent composition of a compound from a chemical formula, one must assume they have 1 mole of the substance. The molar mass of the compound is determined by adding together the molar masses of each individual element as dictated by its subscript in the formula.

Next, the mass of each element is calculated by multiplying its molar mass by the number of atoms of that element in the molecule. This value is divided by the molar mass of the whole compound and then multiplied by 100% to find the percent by mass of that element in the compound.

The percentages add up to 100%, reflecting the total composition of the compound. Thus, the percent composition is a way of expressing what portion of a compound's total mass comes from each constituent element.