[faraz619]

I have some AS chem questions which i have no idea about i dont have a clue what to do, i find it very hard to understand my teacher, the questions are:

1. S + O2 ----> SO2

a sulphuric acid plant uses 2500 tonnes of sulphur dioxide each day. what mass of sulphur must be burned to produce this mass of sulphur dioxide?

can someone explain to me what to do every step they are 5 more questions on these but i'm hoping i will get the jist of it from the first one, alsoi'm finding it hard to understand my chemistry teacher we have to right our own notes based on what he says and he goes to fast and he's just hard to understand can anyone tell me what i should do to do well in che,mistry? get a revision guide or something my notes havent been doing me any favours so far

thanks in advance

[EierVonSatan]

you need to calculate the amount of SO2 (in moles) using the formula {moles = mass (grams)/ RMM} (note: 1 tonne = 1,000kg = 1,000,000g)
after you've done that work out how many moles of sulfer you started with then find grams using the same formula

[faraz619]

sorry can just show me how ou would calculate that please? i'm confused

[Icy_Mikki]

Originally Posted by faraz619

1. S + O2 ----> SO2

a sulphuric acid plant uses 2500 tonnes of sulphur dioxide each day. what mass of sulphur must be burned to produce this mass of sulphur dioxide?

You need to figure out how many moles of sulphur dioxide the plant creates every day. You can do this by figuring out the Relative Atomic Mass of Sulphur Dioxide, and then fitting it along with the mass of 2500 tonnes into this equation:

mass = relative atomic mass * moles

From the formula, you can tell that for every mole of SO2 produced, they have to put one mole of S in- so however many moles of sulphur dioxide the plant uses is the same as how many moles of sulphur is needed. Now, if you find out the relative atomic mass of Sulphur, and then apply it into the same formula as above, but this time with the relative atomic mass and the number of moles known, you can figure out the mass of sulphur needed.

*Relative Atomic Mass equals the total atomic weight of the substance. For an element, this is just its atomic number- Sulphur's is 16. For something like SO2, you have to add up all the atomic numbers of all the parts in it- one sulphur, and two oxygens- sulphur = 16, oxygen = 8 so SO2 = 16 + 2 * 8 = 32

[EierVonSatan]

Originally Posted by faraz619

sorry can just show me how ou would calculate that please? i'm confused

okay moles of SO₂ = 2.5x10⁹/(32 + 16 + 16) = 3.906x10⁷
so moles of S = SO₂ from the equation...
atomic mass of S is 32
so mass of S = 3.906x10⁷ x 32 = 1.25x10⁹g = 1250 tonnes