From the equation below; calculate the mass of sodium hydroxide produced by 2.3g of sodium. [H = 1, O = 16, Na = 23]

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

A. 0.40g
B. 0.80g
C. 4.00g
D. 8.00g

Correct Answer:

Option C – 4.00g

Explanation

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
Relative molecular mass of NaOH = 23 + 16 + 1 = 40gmol-1
2 X 23g of sodium react with water to produce → 2 X 40g of NaOH
∴ 2.3g of sodium will react with water to produce
(2.3 X 40 X 2)/(23 X 2) = 4.00g