Chemical Reactions Notes

Question 1

Chemical reaction

Answer 1

when one or more substances are rearranged to form new different substances

Question 2

Evidence of chemical change

Answer 2

change in color, change in energy, formation of gas, formation of a precipitate, sometimes change in smell

Question 3

Law of conservation

Answer 3

matter and energy can not be created or destroyed, only transformed

Question 4

Synthesis reactions

Answer 4

two substances combine to form one new compound

Question 5

Decomposition reactions

Answer 5

a single substance breaks down into two or more substances

Question 6

Combustion reactions

Answer 6

any reaction that involves O2

Question 7

Combustion of hydrocarbons

Answer 7

a compound made mostly of hydrogen and carbon reacts with Oxygen (O2) to make CO2 and H2O

Question 8

Single replacement reaction

Answer 8

a metal element replaces a cat-ion in a compound or a nonmetal element replaces an anion in a compound

Question 9

Double replacement reactions

Answer 9

the cat-ions of two ionic compounds switch places

Question 10

Aqueous solutions

Answer 10

solutions whose solvent is water

Question 11

spectator ions

Answer 11

ions that do not participate in the reaction