Sulphuric acid + calcium carbonate?

Question

Why does the reaction between sulphuric acid and calcium carbonate produce less effervescence (which is carbon dioxide) than the reaction between hydrochloric acid and calcium carbonate?

uhm, the amount of aq sulphuric acid is added in excess.

Answer 1

H2SO4+CaCO3

vs

HCl + CaCO3

well, this is sort of an incomplete question, but I will assume that it means less effervescence for the same total amount of stoichemetrically correct ingredients

the sulfuric acid molecule is way bigger than the hydrochloric acid molecule so for the same mass of acid, you will have fewer moles of acid and thus the reaction will release fewer moles of CO2

I think that is what they are after with this question, but it is hard to tell with what is provided

Answer 2

Sulphuric acid + calcium carbonate = carbonic acid + calcium sulphate

H2SO4 + CaCO3 = H2CO3 + CaSO4

Answer 3

CaSO4 is not water soluble, Ca Cl2 is. Therefore, CaSO4 solid stays on the surface making it hard for the acid to reach the remaining CaCO3 whereas CaCl2 is in solution enabling the acid to reach the CaCO3 easily.

Answer 4

H2SO4 + CaCO3 ===== H2O + CO2 + CaSO4

whenever an acid reacts with a carbonate, the result will ALWAYS be a salt, carbon dioxide gas and water.


2HCl + CaCO3 ==== H2O + CO2 + CaCl2


And as for your questions, you have to look at the ratio of acid used to CO2 produced in each of the equations. the ratio of H2SO4:CO2 is 1:1 compared to the ratio of HCl:CO2 which is 2:1, therefore the number of moles of carbon dioxide gas produced will always be more even when using the same moles of H2SO4 than HCl.

For example is we have 1 mol of each of those acids reacting with CaCO3:

for H2SO4,
H2SO4 + CaCO3 ===== H2O + CO2 + CaSO4

the ratio of H2SO4:CO2 produced is 1:1. since we have 1 mole of H2SO4, we therefore will have 1 mole of CO2 produced.
I mole of CO2 = 24 dm3 of gas

for HCl
2HCl + CaCO3 ==== H2O + CO2 + CaCl2
the ratio of HCl:CO2 is 2:1. therefore is 1 mole of HCl is used, 0.5 moles of CO2 is produced = 12dm3 of gas.

So you see? there is less effervescence produced with HCl than with H2SO4.