Help me with this question pls

Balance the equation
Ca(s) + 02(g) -CaO(s).
(1 mark)
State the masses of Ca and 0, that completely react together to form 4.488 g CaO. (2)

I’m stuck on the second question where it asks for the masses of Ca and O, how do we calculate that? The answers are 3.2 and 1.28g O2

Reply 1

TypicalNerd

Original post by imbambob

I am assuming you have found a correctly balanced equation, e.g:

2Ca (s) + O2 (g) —> 2CaO (s)

If you look at the equation:
For every 2 moles of Ca that are made, you make 2 moles of CaO, so you can say the ratio of moles of Ca used up to moles of CaO made is 1:1.

Can you first work out how many moles of CaO there are in the 4.488 g and use the above logic to work out how many moles of Ca are needed?