1. 1 mole of an element has a mass = the atomic mass in grams.
2. Gram Formula Mass = the mass of a compound in grams
3. Number of moles = given mass / Gram Formula Mass
4. Given mass = the mass given in the problem.
5. When given a Hydrate. Multiply the mass of water by the coefficient of water then add to the Gram formula mass of the compound.
6. Percent Composition = Part / whole *100
7. Parts per million = part / whole * 1,000,000
8. Molarity is a measure of solution concentration. How much solute is dissolved in a specific amount of solvent.
9. Molarity = moles of solute / Liters of solution
10. Make sure you always use liters in the formula not milliliters.
11. 3M is more concentrated than 2M. 2M is more dilute than 3M.
12. Empirical formula is the reduced form of a molecular formula.
13. Empirical formulas show lowest whole number ratios, molecular formulas show exact numbers of atoms.
14. To Balance equations multiply coefficients * subscripts. Make sure you have the same number of each type of atom on both sides of the equation.
15. Coefficients represent moles.
16. There are 4 major reaction types.
a. Synthesis: A + B à C
b. Decomposition: Cà A + B
c. Single replacement: A + BD à B + AD (activity series)
d. Double replacement: AC + BD à BC + AD
17. Mole-mole calculations: Stoichiometry. Set up a proportion using the equation. Coefficients from the equation will be in the denominators. Moles given in the problem will be in the numerator.
18. Be careful to round to the nearest tenth when asked. Follow rules for significant figures.