Question

This is the chemical formula for talc (the main ingredient in talcum powder):

Answer 1

Answer : 6.41 moles of silicon are in the sample.

Solution : Given,

Moles of magnesium = 9.62 moles

The given chemical formula for talc is, $Mg_3Si_2O_{52}OH_2$

From the given chemical formula we conclude that

The stoichiometry of magnesium and silicon is 3 : 2

3 moles of magnesium is equivalent to 2 moles of silicon

9.62 moles of magnesium will be equivalent to $\frac{2}{3}\times 9.62=6.41$ moles of silicon

Therefore, the number of silicon present in sample are 6.41 moles.