Chemical Reactions

Question 1

What is a diatomic molecule?

Answer 1

A compound made up of only two atoms eg O₂

Question 2

In a chemical reaction, the mass of the reactants (must/must not) equal the mass of the products

Answer 2

Must

Question 2

When balancing equations, do you change the coefficients, subscripts, or both?

Answer 2

Coefficients only

Question 2

What is the Law of Conservation of Mass

Answer 2

The Law of Conservation of Mass states that matter is neither created nor destroyed

Question 3

Balance Fe + O₂ –> Fe₂O₃

Answer 3

4Fe + 3O₂ –> 2Fe₂O₃

Question 3

What are the 4 states of matter?

Answer 3

Solid (s) eg. Fe
Liquid (l) eg. H₂O
Gas (g) eg. O₂
Aqueous solution (aq) eg. NaCl

Question 4

Balance H₂ + O₂ –> H₂O

Answer 4

2H₂ + O₂ –> 2H₂O

Question 5

Balance Zn + CuSO₄ –> Cu + ZnSO₄

Answer 5

It’s already balanced

Question 6

Most elements will be (solid/gas/liquid) or (solid/gas/liquid)

Answer 6

Solid or gas

Question 7

Most compounds will be (solid/liquid/gaseous/aqueous)

Answer 7

Aqueous