Question

calculate the molar mass of nickel (iii)oxide to the nearest tenth place. Give both the numerial value and the units

Answer 1

Nickel (Ni) has the charge as +3 while oxygen (O) has -2. Hence, the chemical formula for the nickel (iii) oxide is Ni₂O₃. 

molar mass of Ni = 58.69 g/mol
molar mass of O = 15.99 g/mol

number of Ni atoms in Ni₂O₃ = 2
Molar mass of Ni in Ni₂O₃ = 2 x 58.69 g/mol = 117.38 g/mol

number of O atoms in Ni₂O₃ = 3
Molar mass of O in Ni₂O₃  = 3 x 15.99 g/mol = 47.97 g/mol


Hence, molar mass of compound = 117.38 g/mol + 47.97 g/mol
                                                          = 165.35 g/mol
                                                          = 165.4 g/mol