A mole is defined as the amount of a substance that contains 6 x 1023 representative particles of a substance. This page will introduce you on how to figure out mole problems such as calculating molar mass, percent compostition from formulas, percent composition from masses of elements, empirical formula from percent composition, and molecular formulas.
1. Multiply the atomic mass of each element in the equation by the number of atoms of the element in the formula.
2. Calculate the total of all the atomic masses.
3. Use the info found in step two and put it into grams. The unit for it is g/mol. Now you have figured out the molar mass.
1. Find the amount of all the atomic masses added together.
2. Divide the total atomic mass of every element by the what you found out in step one. Then multiply your answer by 100.
1. Assume you have 100g of the particular compound and change the percent to grams for every element.
2. Take the grams of each element and multiply them by 1 mole over the molar mass of the selected element.
3. Figure out which element has the lowest amount of moles and divide the moles of the other elements by lowest number of moles.
4. If when divided the answers in step three don't work out to be whole numbers multiply them by a whole number that will make them not have decimals.
1. Figure out the empirical formula.
2. Take the molecular mass and divide it by the empirical formula mass. Any answer over one you must multiply the empirical formula by this number.1
