C4 Quantitative Chemistry

Question 1

Relative atomic mass

Answer 1

• Atoms are too small to weigh individually
• Carbon-12 is used as a standard and is assigned a mass of 12
• Other atoms are given a mass relative to (compared to) carbon-12

Question 2

Calculating % by mass

Answer 2

Number of atoms of the element x Ar of element x 100 / Mr of the compound

Question 3

What is a mole?

Answer 3

The amount of substance that contains the same number of particles in a carbon-12 atom