click below
click below
Normal Size Small Size show me how
Definitions Ch 8
Exam 4
| Question | Answer |
|---|---|
| Atomic mass unit amu | Small unit used to describe the mass of an atom. |
| Average atomic mass | It means that any sample of C can be treated as it were made up of identical carbon atoms. |
| Mole | Unit use to measure the amount of a chemical substance. It helps to convert from particles to mass of a substance. The number of atoms present in 12.01 g of C |
| Avogandro's number | One mole of something is 6.022 x 10^23 units of that substance.(Symbol N) Ex. A mole of water is 6.022 x 10^23 H2O molecules. |
| Molar mass/ Molecular weigh | T: Sum of the atomic masses of each element in a formula B: The mass of 1 mol of the substance (g) (MM)... Remember diatomic elements and count 2 times. |
| Formula weight | Sometimes used to name the molar mass for ionic compounds like NaCl. |
| Percent composition | Gives the mass % of each element in a substance. Formula: Divide the total mass of an element by the total mass of the molecule and then multiply by 100. |
| Empirical Formula (Simplest formula) | The smallest whole-number ratio of elements in a formula. Can be the same for various compounds. |
| Molecular Formula | T: multiple of the empirical formula. B: Gives the composition of the molecules that are present in a compound(Without simplifying). |