Chemistry how many moles

Search for:. Converting between Mass and Number of Moles. Learning Objective Convert between the mass and the number of moles, and the number of atoms, in a given sample of compound. To convert between mass and number of moles, you can use the molar mass of the substance. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet. Licenses and Attributions. The following table provides a reference for the ways in which these various quantities can be manipulated:.

Multiply moles of Ca by the conversion factor The moles cancel, leaving grams of Ca:. The number of atoms can also be calculated using Avogadro's Constant 6. The mole, abbreviated mol, is an SI unit which measures the number of particles in a specific substance. Applications of the Mole The mass of a mole of substance is called the molar mass of that substance. Solution Multiply moles of Ca by the conversion factor molar mass of calcium Grams can be canceled, leaving the moles of K.

Summary The mole, abbreviated mol, is an SI unit which measures the number of particles in a specific substance. Problems Using a periodic table, give the molar mass of the following: H Se Ne Cs Fe Convert to moles and find the total number of atoms. Answers Question 2 1. References Keenan, Charles W. General College Chemistry.

New York: Haper and Row, Mortimer, Charles E. Chemistry a Conceptual Approach. This number is used in chemistry because if you could count out this many carbon atoms, the total mass of carbon you would have is 12 g. On the other hand, weighing out 12 g of carbon allows you to know how many atoms you have. One mole of carbon atoms has a mass of exactly 12 g. Because magnesium atoms each have twice the mass of carbon atoms 24 Mg compared with 12 C , one mole of magnesium has a mass of 24 g.

In fact, one mole of any element has a mass in grams that is equal to its relative atomic mass. One mole of iron has a mass of 56 g. A mole of a molecular compound contains 6 x 10 23 molecules. It has a mass that is equal to its relative formula mass.