An analytical chemist has determined by measurements that there are moles of magnesium in a sample of talc. how many moles of silicon are in the sample

The chemical formula for talc is:

Mg₃ (SiO₂) ₅ (OH) ₂

The formula shows us that there are:

3 moles of magnesium

5 moles of silicon

12 moles of oxygen

2 moles of hydrogen

For every mole of talc

Using this, we can determine the ratio between magnesium and silicon. This is:

3 moles Mg : 5 moles Si

Given a number of moles of magnesium, we may simply multiply by 5/3 to determine the number of moles of silicon present.