Looking to get ready for the ACT? We can help with ACT Prep Therefore, you have 136.2652 g of calcium. Since the atomic mass of calcium is 40.078 amu, the molar mass of calcium is 40.078 g/mole.Ģ) Multiply the number of moles of calcium you have by the molar mass. Therefore, you have 0.4996 mole of nitrogen.Įxample: If you had 3.4 moles of calcium, how many grams of calcium do you have?ġ) Figure out what the molar mass of calcium is. Since the atomic mass of nitrogen is 14.01 amu, the molar mass of nitrogen is 14.01 g/mole.Ģ) Divide the amount of nitrogen you have by the molar mass. The molar mass of water would then be 18.016 g/mole.Įxample: If you had 7 g of nitrogen, how many moles of nitrogen do you have?ġ) Figure out what the molar mass of nitrogen is. The mass will be represented in grams while a mole of a substance is defined as 6.02 x 10 23 representative particles (Avogadros number) of that substance. To get the molar mass of water, you would add up the molar masses of 2 hydrogens (2 x 1.01 g) and 1 oxygen (1 x 16 g). Molar mass is the mass of one mole of a substance. For example, a water molecule is made up of 2 hydrogen atoms and 1 oxygen atom. To get the molar mass for a compound, you add up all the molar masses of the atoms in the compound. Thus, the molar mass of hydrogen is 1.01 g/mole. This means that 1 mole of hydrogen is 1.01 g. the mass of one mole of carbon atoms is 12.011 grams 1 moles of atoms 6.022 x 1023 atoms (Avogadros number, NA). Thus, 1 mole of any element has a mass in grams that is numerically equivalent to its atomic mass.įor example, the atomic mass of hydrogen is 1.01 amu. 12 grams is equal to 1 mole of carbon-12, which has 6.02×10 23 atoms. If we look at 1 atom of carbon-1, it has a mass of 12 amu. Molar mass is used to convert moles to grams.