Conservation Of Mass

Question 1

What is the definition of conservation of mass?

Answer 1

No atoms are created or destroyed (only the bonds between atoms that change)

Question 2

Give an example of this with sodium and chlorine ?

Answer 2

2Na + Cl2 — 2NaCl

Question 3

What should the mass stay as throughout the reaction?

Answer 3

The mass should remain the same
However
Mass might seem to change if there is a gas released as it won’t be measured by the scales

Question 4

Give an example of a reaction which the reactants and products do not have the same weight? Explain why

Answer 4

2 Mg + O2 —- 2MgO
Mg weighs 1g but MgO weighs 1.6g so the the products appear like they are bigger but really the scale just wasn’t able to weight all the reactants

Question 5

How could this be changed ( A reaction with a glass) so both sides have the same mass?

Answer 5

Sealed container/ closed environment
Reaction mass would balance perfectly

Question 6

1. What should you say if a reactant decomposes to form a solid and a gas and the mass appears to of changed?
2. How could you change/ fix that

Answer 6

The gas would float off into the air
Weight of the products would of appeared to decrease
Sealed environment or container