Paper 1: Conservation Of Mass

Question 1

What does the law of conservation of mass state?

Answer 1

The total mass of reactants stays constant during a chemical reaction
Total mass before and after a reaction stays the same

Question 2

What is a closed system?

Answer 2

Where no substances can enter or leave during a reaction

Question 3

What do close systems include?

Answer 3

Reactions in a sealed container
Precipitation reactions in a beaker

Question 4

What is a Non-enclosed system?

Answer 4

Where substances can leave or enter during a reaction

Question 5

What do non-enclosed systems include?

Answer 5

Reactions in an open flask

Question 6

What happens to the mass in a closed system?

Answer 6

Stays the same

Question 7

What happens to the mass in a non-enclosed system?

Answer 7

Mass of a reactive metal increases
Mass of a reactive non-metal decreases

Question 8

Why does the mass of a reactive metal increases in a non-enclosed system?

Answer 8

Oxygen atoms combine with metal atoms to form metal oxides

Question 9

Why does the mass of a reactive non-metal decrease in a non-enclosed system?

Answer 9

Products in the gas state escapes from the containers