Answer to Question #256677 in General Chemistry for Theresa Stewart

Question

Calculate the number of moles present in the following using the formula . number of moles = molar mass 1)40g of Mgo

2)25 of AgNo3

Answer 1

The molar masses are:

MgO - 40.30 g/mol;

AgNO₃ - 169.87 g/mol.

a)

$Moles\ MgO=\frac{mass}{molar\ mass}=\frac{40\ g}{40.30\ g/mol}=0.99\ mol$

b)

$Moles\ AgNO_3=\frac{mass}{molar\ mass}=\frac{25\ g}{169.87\ g/mol}=0.15\ mol$