The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

A level chemistry

15.0g of SiO2 and 8.5g of carbon are heated together to form silicon carbide and carbon monoxide.SiO2 3C = SiC 2CO. Can somebody tell me why silicon dioxide is an excess reactant in this reaction
(edited 2 years ago)
using the respective masses and Mr, can you work out the moles of SiO2 and C present?
Reply 2
Avatar for yhh65
yhh65
OP
10
Original post by bl0bf1sh
using the respective masses and Mr, can you work out the moles of SiO2 and C present?

Yes and I got
Moles for SiO2=0.25 and C= 0.7083
have a look at the ratio SiO2:C in the equation
using your calculated numbers, how many moles of SiO2 are needed to react with the C present (or vice versa)?
Reply 4
Avatar for yhh65
yhh65
OP
10
Original post by bl0bf1sh
have a look at the ratio SiO2:C in the equation
using your calculated numbers, how many moles of SiO2 are needed to react with the C present (or vice versa)?

0.25 moles of SiO2 is needed to react with 0.2361 or 0.24 moles of C
and how many moles of C are actually present?
Reply 6
Avatar for yhh65
yhh65
OP
10
Original post by bl0bf1sh
and how many moles of C are actually present?

0.7082
so which is the limiting reagent?
(i.e. the other must be in excess)
Reply 8
Avatar for yhh65
yhh65
OP
10
Original post by bl0bf1sh
so which is the limiting reagent?
(i.e. the other must be in excess)

carbon
so SiO2 is in excess! boom :smile: well done
Reply 10
Avatar for yhh65
yhh65
OP
10
Original post by bl0bf1sh
so SiO2 is in excess! boom :smile: well done

Thank you :smile:

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you