Chemistry problems, help anyone??

Question

hey everyone!

I've been absent from my school for around 2 weeks, and my major assignment for chemistry SACE is due soon.

I"m spending tonnes of extra time on it, but I can't get it.

could anyone help me with the questions? and if you can show the working out so i can figure out how you did it, that'd be swell, but it's 'kay if not.

6.5 grams of zinc is dissolved in dilute sulphuric acid. calculate the minimum amount of acid required in grams to convert all the zinc into zinc sulphate.

Zn+H2SO4---------->ZnSO4+H2

and

calculate the mass of hydrogen gas evolved in the reaction above

cheers sooo much if anyone can lend me a hand!!!

Aloha

Answer 1

a)For n mol Zn you need n mol H2SO4.

n= m(Zn)/M(Zn)=m(H2SO4)/M(H2SO4)

m: masses; M: molecular weights

Zn: M=65.41 g/mol

H2SO4: M=98 g/mol

Rearranging for m(H2SO4) and inserting given values : m(H2SO4)=9.73 g

b) Same equation as in a) but wirh molecular weights and masses of H2 instead of H2SO4