How do you calculate the amount of moles of a (solid) substance from its mass?

Use the equation:Moles = Mass ÷ Relative mass
For example: How many moles are there in 10g of CaCO3 ? ( to 3 significant figures)Find the relative mass of CaCO3 by adding up the masses of the atoms that make it up.Ca = 40C =12O = 16
1 x Ca + 1 x C + 3 x O = 40 + 12 + 3 x 16 = 100 = relative mass
Moles = Mass ÷ Relative mass = 10 ÷ 100 = 0.100 moles (3 s.f.)

AJ

Related Chemistry GCSE answers

All answers ▸

2.4 g of magnesium reacts with 1.6 g of oxygen. What is the empirical formula of the oxide formed?


How can an explosion be explained by the different ways molecules are packed together in solids, liquids and gases?


Why is graphite softer than diamond if they are made up from the same covalently bonded carbon atoms?


Will a solid ionic compound conduct electricity ?