Question

The chemical formula for barium oxide is BaO.A chemist determined to measurements that 0.020 moles of barium oxide participated in a chemical reaction. Calculate the mass of the barium oxide that participates. Be sure your answer has the correct number of significant digits

Answer 1

Given :

• 0.020 moles of barium oxide participated in a chemical reaction.

,

• Molecular mass for BaO = (137.327+16 ) = 153.33g/mol

• We will the following formula:

n = mass Bao/Molecular Mass BaO

therefore Mass BaO = n*Molecular Mass

Mass = 0.020mol* 153.33g/mol

=3.0666g

• This means that the correct number of significant digits

(Mass ) =3.07 g

(extra notes: because of 0.020 has 3 significant figures , so our answer will also need to be expressed with 3 signicant figures )