[whoooosh]

on quite a few of the old practical papers i have tried
on the evaluating section you are asked for the inaccuracies of a gas collection method
ive got:
a small mass of metal will give a high percentage error
some reactions are exothermic so will heat up the gas, so it seems like more has been given off
and the gas syringe is not accurately calibrated

anyone got anymore ??

also why a titration is better than gas collection

thanks =]

[cliverlong]

Wouldn't you list the different gas collection methods then tackle them one-by-one?

Clive