[jamesbrown]

Hello I was just wanting to check if I got this question right.

How much sulphur dioxide would be made from 320 tonnes of sulfur.
If the equation is S+O₂=SO₂
that would mean the ratio would be 1 : 1 : 2
Also the mass would be 32 : 32 : 64
Which means that i would have to double the amount of Sulphur so it would be 320*2 = 640 tonnes
Is that right?

[Hunter2]

Yes corrrect. Better is to calculate via mole. 320 t Sulphur  corresponds 10000 kmol.  This correspond also to the SO₂ . With the molar mass of 64 kg/kmol gives 640 t.

[jamesbrown]

If 48 tonnes of iron ore is used in a blast furnace what would the the mass of iron be. If the equation is:
Fe₂O₃ + 3CO = 2Fe + 3CO₂

Would I find the moles of iron oxide.
But I'm not really sure what to do after that?

Can someone help please It would be really helpful.

Thanks

[Hunter2]

You calculate the moles of the 48 t Iron oxide.

If you have that then you can see the ratio of the moles of iron oxide to iron in the equation.

With the new mole value you calculate backwards to the mass of iron.

You need the molar masses of iron oxide and iron itself.

[AWK]

Just read the balanced reaction - one mole of Fe₂O₃ gives 2 moles of Fe.

[jamesbrown]

So the moles of Iron oxide is 300000
So does that mean iron has 120000 moles
and oxygen has 180000 moles
and because in the equation we are making 2 iron does that mean the moles of iron is 120000*2=240000
then we need to find the mass of it so would it be i don't know could someone help?

[Hunter2]

No you get 300000 mole Fe₂O₃. This correspond according the equation to the double amount of iron. So the moles of Fe is 600000 moles.

This you have to calculate back to the mass of iron.

[jamesbrown]

Can someone just give me a step by step method on how do do mole questions like these. I'm really trying to understand but Its quite complicated in my opinion. Here are a list of the question that I have to do. So yeah. Thank you for trying to help someone dumb like me.

[Burner]

If I am not mistaken,

(Number of moles)=(mass)/(molar mass)

So, (mass)=(Number of moles)*(molar mass)

Moreover, we uses mole ratio directly from the balanced equation. Take question 2 as an example, you have 300000 mol of Fe₂O₃. From the balanced equation, mole ratio of Fe₂O₃ and Fe is 1:2, i.e. 1 mol of Fe₂O₃ gives 2 mol of Fe. Thus, 300000 mol of Fe₂O₃ gives 600000 mol of Fe. Then, you have to multiply that 600000 mol of Fe with its molar mass, which is 56. Finally, you get 600000*56=33600000g of Fe, or 33.6 tonnes of Fe.

Please kindly correct me if I have made any mistakes.

[Hunter2]

Generally the steps are:
1. Write chemical equation if it is not given.
2. Calculate the given mass into moles as described n = m/M, n [mole], m [mass] and M [molar mass]
3. Check how much moles correspond to the material what you looking for (Fe₂O₃ to Fe here 1:2)
4. Calculate back to the mass with the formula given in 2.

[jamesbrown]

For question 3 I have worked out the amount of moles for sodium chloride which is 136752.1368
but then for the ratio would it be 3:2:1 so i would have 91168.0912 moles of sodium and then i would have 45584.0456 mole of chlorine.
Is this right I don't know.
Then if this is right what would i do next?

[Hunter2]

First calculate the mole NaCl  n = 16000 kg/58,5 kg/Kmol =273,5 kmol

In the equation you can see that the mole amount of sodium is the same like the NaCl. So the given moles multiplited with the molar mass of sodium gives 6290,59 kg

For the Chlorine you see its the half it gives then 9695,73 kg

[jamesbrown]

Hunter why did you not convert the mas into grams and why did you not work out the moles for 2nacl because you only worked out the moles for nacl

[Hunter2]

What do you mean, I didn't convert the mass in gram. The mass is given in gram. 16 t = 16000 kg and this is equal to 273,5 kmol.

The equation is 2 NaCl => 2 Na + Cl₂

So 2 NaCl correspond to 2 Na. This  is the same like NaCl correspond to Na. You can erase the 2 on both sides.

And 2 NaCl to Cl₂ is the same like NaCl to 0.5 Cl₂

[jamesbrown]

Sorry i meant why did you convert it to kg not grams