Answer:
1. 57.5%
2. 27.89 g
Explanation:
1. Determination of the percentage of sodium in sodium hydroxide.
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mass of Na in NaOH = 23 g
Percentage of Na = mass of Na / Molar mass of NaOH × 100
Percentage of Na = 23/40 × 100
Percentage of Na = 57.5%
2. Determination of the mass of sodium in 48.5 g of sodium hydroxide.
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mass of Na in NaOH = 23 g
Total mass of NaOH = 48.5 g
Mass composition of Na = mass of Na / Molar mass of NaOH × Total mass
Mass composition of Na = 23/40 × 48.5
Mass composition of Na = 27.89 g