AS level chemistry- help

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#1
Magnesium carbonate reacts with hydrochloric acid.

MgCO3(s) + 2HCl(aq) → MgCl2(aq) + CO2(g) + H2O(l)

(a) What mass of magnesium carbonate would react with excess hydrochloric acid to produce 240cm3 of carbon dioxide, measured at room temperature and pressure?

Data: 1mol of any gas occupies 24.0dm3 at room temperature and pressure
Molar mass of magnesium carbonate = 84.3gmol−1

A 0.843g
B 8.43g
C 84.3g
D 843g

The answer is A but i don't know how
0
1 month ago
#2
(Original post by a.f.x.d)
Magnesium carbonate reacts with hydrochloric acid.

MgCO3(s) + 2HCl(aq) → MgCl2(aq) + CO2(g) + H2O(l)

(a) What mass of magnesium carbonate would react with excess hydrochloric acid to produce 240cm3 of carbon dioxide, measured at room temperature and pressure?

Data: 1mol of any gas occupies 24.0dm3 at room temperature and pressure
Molar mass of magnesium carbonate = 84.3gmol−1

A 0.843g
B 8.43g
C 84.3g
D 843g

The answer is A but i don't know how
The clue here is in the units used for the gas, and you need to be eagle eyed to spot that the question ask for how much CO2 in cm3, and your data is in dm3

By way of illustration, convert both volumes to m3:

24.0dm3 = 24 x 10-1 m3, which = 2.4 x 10-2 m3
240cm3 = 240 x 10-2 m3, which = 2.4 x 10-4 m3

Can you take it from there?
0
1 month ago
#3
Another clue, now you've got the units straight is how many moles of CO2 are you producing from the stoichiometry?
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