N. Calculate the number of moles of magnesium oxide, MgO in i. 80 g and ii. 10 g of the compound.

Question

4) Solve problems

N. Calculate the number of moles of magnesium oxide, MgO in i. 80 g and ii. 10 g of the compound. (Average atomic masses of Mg = 24 and O = 16)

Answer 1

Molar mass of MgO= (atomic mass of Mg)+(atomic mass of O)

=24+16

=40 g/mol

1) 80g of MgO

number of mol = \(Given \space mass \over Molar \space mass\) 

=\({80\over 40}=2mol\) 

2) 10 g of MgO 

number of mol =\(Given \space mass \over Molar \space mass\) 

=\({10\over 40}=0.25 mol\)