Chemical Equation Stoichiometry: Calculating Mass of Reactants

How much sodium is required to react with 4.5 moles of chloride?

103.5 g of sodium would be needed to react with 4.5 moles of chloride ions. Therefore, the correct option is (B).

The balanced chemical equation Na+ + Cl → NaCl tells us that 1 mole of sodium ions (Na+) reacts with 1 mole of chloride ions (Cl-) to produce 1 mole of sodium chloride (NaCl). Therefore, to react with 4.5 moles of chloride, we need an equal number of moles of sodium. This is because the reactants must be present in the stoichiometric ratio of 1:1 to ensure complete reaction.

Moles of Na+ required = moles of Cl- = 4.5 mol

The molar mass of Na+ is 23 g/mol, so the mass of sodium required is:

Mass of Na+ = Moles of Na+ x Molar mass of Na+

Mass of Na+ = 4.5 mol x 23 g/mol = 103.5 g

Understanding the concept of molar mass is crucial in stoichiometry calculations. It represents the mass of one mole of a substance and is used to convert between moles and grams.