Hard Chemistry calculations

Does anyone know how to do them?

The percent yeild one is easy. According to the balanced equation, for every mol of sulfur dioxide, a mol of sulfur trioxide is produced.

so convert 1000g of sulfur dioxide into moles and do the same for sulfur trioxide

S - 32.065
O2 - 16 + 16 = 32

total molar mass of SO2 is 64.025 mols per gram.

1000 g ÷ 64.025 g/mol [grams cancel out and you're left with moles]

that's 15.6189 mols in 1000g of sulfur dioxide.

Now do the same for sulfur trioxide:

S - 32.065
O3 - 16 + 16 + 16 = 48

48 + 32.065 = 80.065

1225÷80.065 = 15.3 mol

now we know that 15.3 mols of SO3 was produced from 15.6 mols of SO2. theoritically 15.6 mols of SO3 should have been produced. But that's obviously not the case.

just find the percentage of these two

15.3/15.6 * 100% = 97.96%

Bunyip can. :]

I have no idea what you guys are talking about

I used to be able to do the first question, just forgot how to do it. I'm doing grade 12 chem this year but we're only on organic chemistry, I don't think we'll even cover stoichiometry well this year due to a tight schedule. I'm sure that question is grade 11 level stoichiometry.

When in doubt, just convert to mols and move around some numbers and do some algebra until the numbers start clicking.

Ha I'm in Gr. 7

I hope this helps :) (correct me if I’m wrong)

Chemistry makes my brain hurt...

I just only know:
Co(cobalt)+2Fe(iron)=coffee
Ba(barium)+2Na(sodium)=banana

Just kidding don’t take it too serious.

Thanks @LimitlessGuap @Tae7