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# What Mass of CO2 is produced when 35g of Calcium Carbonate is Decomposed watch

1. Please go through the steps involved and why please. Its my first time doing A Level Chemistry :/

Formula
CaCO3 -> CO2+CA
2. (Original post by ItsUmzy)
Please go through the steps involved and why please. Its my first time doing A Level Chemistry :/

Formula
CaCO3 -> CO2+CA
Your equation is wrong.
It should be:

CaCO3 -> CaO+CO2

Do you know how to work out moles?

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3. (Original post by HAnwar)
Your equation is wrong.
It should be:

CaCO3 -> CaO+CO2

Do you know how to work out moles?

Posted from TSR Mobile
I knew there was something wrong about it... :/
and Kind Of.... In this case would it be 35/100.1?
4. (Original post by ItsUmzy)
I knew there was something wrong about it... :/
and Kind Of.... In this case would it be 35/100.1?
Yeah that's fine.
So that's your moles for calcium carbonate.

Now it's a one to one ratio with carbon dioxide, so now you have the moles of CO2, how would you find its mass?
5. (Original post by HAnwar)
Yeah that's fine.
So that's your moles for calcium carbonate.

Now it's a one to one ratio with carbon dioxide, so now you have the moles of CO2, how would you find its mass?
Multiply it by its Mr? (60)?
6. (Original post by ItsUmzy)
Please go through the steps involved and why please. Its my first time doing A Level Chemistry :/

Formula
CaCO3 -> CO2+CA
I assume you mean CaCO3 -> CO2+CaO which is already balanced

The relative molecular mass of CaCO3 is 40+12+16+16+16=100
The relative molecular mass of CO2 is 12+16+16=42

So 1g of CaCO3 -> 0.42g of CO2. Times both sides by 100 (because you're finding it out for 100g) and you get 100g of CaCO3 -> 42g of CO2
7. (Original post by ItsUmzy)
Multiply it by its Mr? (60)?
Your Mr is wrong it's 44 (12+16+16), but other than that you got it
8. (Original post by HAnwar)
Your Mr is wrong it's 44 (12+16+16), but other than that you got it
Ohhh! Thanks for that, the ratio thing confuses me a lot. Chemistry GCSE was Ok for me but A Level is really separating the men from the boys
9. (Original post by ItsUmzy)
Ohhh! Thanks for that, the ratio thing confuses me a lot. Chemistry GCSE was Ok for me but A Level is really separating the men from the boys
No problem.

What part do you find confusing with ratios?
10. (Original post by HAnwar)
No problem.

What part do you find confusing with ratios?
Just how and why they are proportioned and what part of the equation is "ratio'd" like i have one question now
WHat mass of Carbon Monoxide is produced when 1000kg of TNT is Defused/Decomposed idek haha
11. (Original post by ItsUmzy)
Just how and why they are proportioned and what part of the equation is "ratio'd" like i have one question now
WHat mass of Carbon Monoxide is produced when 1000kg of TNT is Defused/Decomposed idek haha
It's not hard finding the ratio. You just have to look at the number in front of the reactants/products.

Ok so do they give you an equation for this?
12. (Original post by HAnwar)
It's not hard finding the ratio. You just have to look at the number in front of the reactants/products.

Ok so do they give you an equation for this?
Yep
2 C7 H5 (NO2)3 -> 12CO+5 H2+ 3 N2 + 2 C
What ive done is get the Mr of the first part which i got as 227, then divided that by 1000, and have 0.227
no clue what to do next
is it a 1:6 Ratio
13. (Original post by ItsUmzy)
Yep
2 C7 H5 (NO2)3 -> 12CO+5 H2+ 3 N2 + 2 C
What ive done is get the Mr of the first part which i got as 227, then divided that by 1000, and have 0.227
no clue what to do next
is it a 1:6 Ratio
Are you sure your Mr is right?

Because I'm getting a different answer.

And you would times by 1000 as when you convert kg to g you multiply by 1000.
14. (Original post by HAnwar)
Are you sure your Mr is right?

Because I'm getting a different answer.

And you would times by 1000 as when you convert kg to g you multiply by 1000.
(12*7)+(1*5)+((14+16*2)*3)
=227 don't it? Im so confused :s
15. (Original post by ItsUmzy)
Please go through the steps involved and why please. Its my first time doing A Level Chemistry :/

Formula
CaCO3 -> CO2+CA
CaCO3 → CO2 + CaO

n = m/M n = moles, m = mass, M = molar mass/relative molecular mass (technically, the values of the periodic table added up.)
n = 35g / 40.1 + 12 + 3(16)
n = 0.350

Ratio of CaCO3 to CO2
1 : 1
(If it was 1 to 2, 1:2, you double, for example, if it was 2 to 1, 2:1, you divide, for example.)

m = nM (or n x M, that's just how I write things.)
m = 0.350 x (12 + 2(16))
m = 15.4g

I know it's already been sorted out, but the more ways I see a problem for example, the easier it is to understand.
16. (Original post by XcitingStuart)
CaCO3 → CO2 + CaO

n = m/M n = moles, m = mass, M = molar mass/relative molecular mass (technically, the values of the periodic table added up.)
n = 35g / 40.1 + 12 + 3(16)
n = 0.350

Ratio of CaCO3 to CO2
1 : 1
(If it was 1 to 2, 1:2, you double, for example, if it was 2 to 1, 2:1, you divide, for example.)

m = nM (or n x M, that's just how I write things.)
m = 0.350 x (12 + 2(16))
m = 15.4g

I know it's already been sorted out, but the more ways I see a problem for example, the easier it is to understand.
Thanks!
How would i do it for
WHat mass of Carbon Monoxide is produced when 1000kg of TNT

2 C7 H5 (NO2)3 -> 12CO+5 H2+ 3 N2 + 2 C
17. (Original post by ItsUmzy)
(12*7)+(1*5)+((14+16*2)*3)
=227 don't it? Im so confused :s
Sorry you're right. I mis typed in my calculator.

Now you times 1000kg by 1000 to get grams.

Do that and get the mass, now divide it by the Mr of TNT.

There is a 2:12 ratio.

To make it simpler, divide your answer by two, and then times by 12 to get the moles for CO.
Does that make sense?

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18. (Original post by HAnwar)
Sorry you're right. I mis typed in my calculator.

Now you times 1000kg by 1000 to get grams.

Do that and get the mass, now divide it by the Mr of TNT.

There is a 2:12 ratio.

To make it simpler, divide your answer by one, and then times by 12 to get the moles for CO.
Does that make sense?

Posted from TSR Mobile
could it not simplify to a 1:6 ratio

and i get 2.27*10^-4, what will i multiply it with from here
19. (Original post by ItsUmzy)
could it not simplify to a 1:6 ratio

and i get 2.27*10^-4, what will i multiply it with from here
Or yeah you could do that haha

(Just as a side note, if you have a weird ratio like 2:3, you can get your moles for e.g. 2.27x10^-4 and then times it by your ratio like this 3/2 as a fraction. This is when you can't simplify)

Now you would times by 6.
That will be your new moles for CO.
Then you just work out the mass from there by multiplying moles with Mr.
20. (Original post by HAnwar)
Or yeah you could do that haha

(Just as a side note, if you have a weird ratio like 2:3, you can get your moles for e.g. 2.27x10^-4 and then times it by your ratio like this 3/2 as a fraction. This is when you can't simplify)

Now you would times by 6.
That will be your new moles for CO.
Then you just work out the mass from there by multiplying moles with Mr.
2.27*10^-4)*6=1.362*10^3
then would i times it by (CO =12+16)???

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