Question

How many atoms of oxygen are in 0.100 mol of silicon dioxide?

Answer 1

1) Silicon dioxide formula: SiO2  ....... 2 is a subscript for the O atom

2) From the formula you have 1 molecula of SiO2 contains 1 atom of SiO2

3) Then, 0.100 mol of SiO2 contains 0.1 mol of Si

4) Multiply by Avogadro's number: 0.100mol *  6.022*10^23 atoms/mol= 6.02*10^22 atoms

Answer: 6.02*10^22 atoms