You are Here: Home

# higher chemistry watch

1. silicon carbide, used for cutting and grinding tools, is made by the reaction of silicon dioxide with carbon graphite. SIO2+3C=SIC+"CO if 100g of SIO2 and 100g of C are reacted as far as possible, which one of the following statements will be correct? a) 111g of SIO2 will be left over
b) 44g of SIO2 will be left over
c) 82g of C will be left over
d) 40g of C will be left over
2. (Original post by jackiemcnair)
silicon carbide, used for cutting and grinding tools, is made by the reaction of silicon dioxide with carbon graphite. SIO2+3C=SIC+"CO if 100g of SIO2 and 100g of C are reacted as far as possible, which one of the following statements will be correct? a) 111g of SIO2 will be left over
b) 44g of SIO2 will be left over
c) 82g of C will be left over
d) 40g of C will be left over
Hey,
I would say the answer is D.
The reaction is SiO2 + 3C --> SiC + 2CO
SiO2: 60.1
100/60.1=1.66mol
C:12
100/12=8.33mol

You can see that the graphite is excess as only 4.99mol of graphite was required for a complete reaction.

Substrat the moles, 8.33-4.99=3.34mol
12x3.34=40.1g
3. (Original post by jackiemcnair)
silicon carbide, used for cutting and grinding tools, is made by the reaction of silicon dioxide with carbon graphite. SIO2+3C=SIC+"CO if 100g of SIO2 and 100g of C are reacted as far as possible, which one of the following statements will be correct? a) 111g of SIO2 will be left over
b) 44g of SIO2 will be left over
c) 82g of C will be left over
d) 40g of C will be left over
If you have any more questions about higher chemistry, you can post them here on the CfE Higher Chemistry thread:http://www.thestudentroom.co.uk/show....php?t=4282042
4. (Original post by mat7276)
Hey,
I would say the answer is D.
The reaction is SiO2 + 3C --> SiC + 2CO
SiO2: 60.1
100/60.1=1.66mol
C:12
100/12=8.33mol

You can see that the graphite is excess as only 4.99mol of graphite was required for a complete reaction.

Substrat the moles, 8.33-4.99=3.34mol
12x3.34=40.1g
thank you

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 29, 2016
The home of Results and Clearing

### 3,398

people online now

### 1,567,000

students helped last year
Today on TSR

Hang on, have Edexcel's come out already?

### University open days

1. SAE Institute
Animation, Audio, Film, Games, Music, Business, Web Further education
Thu, 16 Aug '18
2. Bournemouth University
Fri, 17 Aug '18
3. University of Bolton