[Fortification]

Hi everyone... a quick question here.

HCl reacted with a powdered excess of calcium carbonate and 1.2 dm3 of carbon dioxide is released. The same volume and concentration of methanoic acid also reacts with the same mass of calcium carbonate and gives off 1.2dm3 of carbon dioxide at a slower rate.

Using your theory of reaction rates and equilibrium, explain why

a) methanoic acid takes a longer time to give off the carbon dioxide

b) why the volume of carbon dioxide at the end of the reaction is the same.


For a) I thought it it could possibly be a result of bonding? HCl is an ionic structure whereas methanoic acid is covalently bonded. But the Q says using your theory of reaction rates, so I don't think that this is right. I have no idea for b).

These 2 Qs are from the end of an exam AS paper only worth 2 marks each so they're not expecting much but I can't think of anything.

Any advice would be much appreciated. Thanks.

[Borek]

Write both reaction equations - that'll be answer for b. Net ionic will be a hint for a.

[Fortification]

Oh dear, this is quite embarrassing but what does methanoic acid and calcium carbonate form? carbon dioxide water and ...I got Ca(HCOO)2 as the third product but I'm not sure that's quite right.

[Borek]

Ca(HCOO)₂

OK. Calcium methanoate.