Question | Answer |
starting material in a chemical reaction | reactants |
ending material in a chemical reaction | products |
speeds up chemical reactions | catalyst |
CxHy + O2 --> CO2 + H2O | combustion reaction |
AB --> A + B | decomposition reaction |
A + B --> AB | synthesis reaction |
AB + CD --> AD + CB | double replacement reaction |
AB + C --> CB + A | single replacement reaction |
numbers that are added to balance a chemical equation | coefficients |
numbers NEVER changed to balance a chemical equation | subscripts |
chemical equation that does not have equal # of atoms on both sides | skeleton equation |
chemical equation that does have equal # of atoms on both sides | balanced equation |
gas formed, transfer of energy, color change, precipitate forms | clues of chemical change |
means yields ; shows that chemical reaction is NOT reversible | single arrow |
Double replacement reactions happen this % of the time | 100% |
solid made from mixing liquids | precipitate |
means yields ; shows that chemical reaction goes in both direction | double arrows |
happens when products and reactants are formed at same rate | equilibrium |
law of conservation of mass | states that mass is not created or destroyed in a chemical reaction |
law of conservation of energy | states that energy is not created or destroyed in a chemical reaction |
monatomic | means 1 atom ; is true for most elements |
diatomic | means 2 atoms ; H , N, O , F , Cl , Br, I |
tetratomic | means 4 atoms ; P & As |
octatomic | means 8 atoms ; S & Se |
polyatomic | means many atoms |
Avogadro's number | 6.02 x 10^23 representative particles |
mole | SI unit for amount of substance |