Using the molar volume in calculations with chemical equations
4 marks · NormalHydrochloric acid reacts with sodium carbonate to produce sodium chloride, carbon dioxide and water. The balanced equation is:
Calculate the number of moles in 1.06 g of sodium carbonate. (Ar: Na = 23, C = 12, O = 16)
Calculate the volume, in dm³, of carbon dioxide produced at rtp by this mass of sodium carbonate. (Molar volume at rtp = 24 dm³)
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) 0.01 mol
(b) 0.24 dm³ dm^3
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Marking points
M1 (a) · 1 mark · Correct calculation or method for Mr(Na2CO3) (23×2 +12 +16×3 = 106)
A1 (a) · 1 mark · Correct calculation of moles (1.06/106 = 0.01 mol) (follow-through)
M2 (b) · 1 mark · Correct use of chemical equation (1:1 ratio from Na2CO3 to CO2), and use of molar volume
A2 (b) · 1 mark · Correct answer for gas volume (0.01 × 24 = 0.24 dm³) (follow-through)
Worked solution
a)
b)
From equation: 1 mol Na₂CO₃ produces 1 mol CO₂.