Explanation:
20g of Na and 10g of Cl2 which is in excess?
The equation of the reaction is given as;
2 Na + Cl2 --> 2 NaCl
From the equation;
2 mol of Na reacts with 1 mol of Cl2
Converting the masses of reactants given to mol
Number of moles = Mass / Molar mass
Na;
Number of moles = 20 / 23 = 0.8696 mol
Cl2;
Number of moles = 10 / 71 = 0.1408 mol
In the chemical equation, the ratio was 2: 1 however with the masses, we can tell that Na is in by far excess.
0.8696 mol of Na would require 0.4348 of Cl2 (Present = 0.1408 mol)
This means;
Na - Excess Reactant
Cl2 - Limiting Reactant
Second part; How much NaCl would be produced?
The limiting reactant determines how much of the product is formed.
From the equation of the reactant;
1 mol of Cl2 produces 2 mol of NaCl
0.1408 mol of Cl2 would require x mol of NaCl
1 = 2
0.1408 = x
x = 0.2816 mol of NaCl
Converting to mass;
Mass = Molar Mass * Number of moles
Mass = 58.44 g/mol * 0.2816 mol
Mass = 16.46 g
