Homework Help: Calculating Mass from Chemical Reaction Equations

[Kiah Palmer]

Homework Statement

1. a) The first step in the production of sulphuric acid consists of burning sulphur to produce sulphur (IV) oxide. What’s the mass of sulphur required to produce 6.0 t of sulphur (IV) oxide?

b) A reaction is then brought about between sulphur (IV) oxide and oxygen in the presence of a catalyst to form sulphur (VI) oxide. What’s the mass of sulphur (VI) oxide produced from 6.0 t of sulphur (IV) oxide?

Relevant Equations

The unbalanced equations below will help you with questions

S8 + O2 -> SO2
SO2 + O2 -> SO3

1a) Step 1: Balance the equation - S8 + O2 -> SO2 = S8 + 8O2 -> 8SO2
Conversion (t to g) 6.00 t = 6x10^6 g
Molar mass SO2 = 23 + (2 x 16) = 64 g/mol
6x10^6 g / 64 g/mol = 9.375x10^4 mol SO2
reqired amount Sulphur = 9.375x10^4 mol / 8 mol = 1.172x10^4 mol S8
Molar mass S8 = (8 x 32) g/mol = 256 g/mol

256 g/mol x (1.172x10^4) mol = 3.0x10^6g S8 = 3.0 t S8

1b) Step 1: Balance the equation - SO2 + O2 -> SO3 = 2SO2 + O2 -> 2SO3
Molar mass SO3 = 32 + (3 x 16) = 80 g/mol
Molar Mass SO2 = 32 + (2 x 16) = 64 g/mol
(80 g/mol) / (64 g/mol) = 1.25 g/mol x 6.0x10^6 = 7.5 x 10^6 g = 7.5 tNOTE: I am pretty sure that 1a) is correct, however, it is the last part of question 1b) that I am having a bit of difficulty with. I have tried looking it up, however, the answers I am finding aren't making much sense either. Thank you in advance for your help, it is greatly appreciated.

 

[Borek]

Both answers look OK.

 

[Kiah Palmer]

Both answers look OK.

Thanks! I actually also sent it to my teacher as well through messages and she said the same. I had sent it here just in case she didn't have a chance to respond. :)

 

[Borek]

Calculation done with grams, not tonnes, but it is a ratio that matters.

 

[Kiah Palmer]

great! thanks!