unit 2 chemistry

What are 6 ways to know there was a chemical reaction

• colour change

• Bubbles / gas production

• Template change / heat released or absorbed

• Precipitate forms / solid from two liquids

• Light emission

• New substance formed

What reaction is this

2H2 + O2 ~> 2H2O

Synthesis, when they join to create one

What type of reaction is this?

2H2O ~> 2H2 + O2

Decomposition, when they separate into singles

What type of reaction is this?

Zn + CuSo4 ~> ZnSO4 + Cu

Single displacement, uses reactivity chart, metal takes from the other reaction

What reaction is this?

AgNO3 + NaCl ~> AgCl + NaNO3

Double displacement, both reactions swap their pair

What reaction is this?

CH4 + 2O2 ~> CO2 + 2H2O

Combustion

What is the law of conservation of mass

The theory of “mass is not created or destroyed in chemical reactions”

When balancing equations what has to happen.

The SAME # of each atom on both sides of the equations

what is a precipitate

A precipitate is a solid forming in two liquids

What is the most reactive element in a single displacement

Potassium (K)

What is the least reactive element in single displacement

Gold (Au)

What elements are always soluble

Hint ( NAG SAG )

Nitrates

Acetates

Group 1

Surfaces

Ammonium

Group 17