volumes of gas (1 Viewer)

[rhia]

was wondering if someone would be able to tell me if my answer to this problem is correct.

Q:
Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + H₂O(l) + CO₂(g)

A student mixed some sodium carbonate with an excess of hydrochloric acid in a beaker. The reaction mixture lost mass, due to 700mL of carbon dioxide gas escaping. If the student evaporated the mixture to obtain sodium chloride crysals, what mass of NaCl(s) would he obtain? The molar volume of gases at 100.0 kPa and 25˚C is 24.784 L.

A:
number of moles of CO₂ produced = 1
number of moles of NaCl produced = 2

volume of CO₂ = 0.7L
number of moles of CO₂ = 0.7 ÷ 24.5 = 0.028571428 moles
(mass of CO₂ = (0.7 ÷ 24.5) × 44 = 1.257142857

moles of NaCl = 2 × (0.7 ÷ 24.5) = 0.057142857
mass of NaCl = 0.057142857 × (23 + 35) = 3.314285706 g


ignore my non-attempt at rounding, at which i suck.

 

[Riviet]

Looks right to me, other than the rounding, which you should only do in the final answer. You should also use the value given to you in the question for the volume of gas at that pressure + temperature (24.78 is sufficient).

 

[rhia]

Looks right to me, other than the rounding, which you should only do in the final answer. You should also use the value given to you in the question for the volume of gas at that pressure + temperature (24.78 is sufficient).

cheers, have re-done using provided value.