The number of mole of a molecule is defined as its mass per molar mass. Using # mol = n, mass = m and molar mass = M and given that n = M m , rearrange this expression for (a) M = ? (b) m = ? (c) If n = 0.0021 mol and M = 44 g/mol; what is the value of m?
Evaluating the expression and cancelling units, we obtain,
m = 0.0924 grams
M is the molar mass. This value is very useful in chemistry calculations especially in calculating the amounts of reactants and products for a chemical reaction.
