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Moles help :)

Can someone help me with this question I think I am messing something up :redface:

2a) Balance the equation below

Pb(NO3)2(s) ---> PbO(s) + NO2(g)+02(g)
I got:

2Pb(NO3)2(s) ---> 2PbO(s) + 4NO2(g)+02(g)

which seems fine.

b). What is the total volume of gas measured at RTP, formed by the decomposition of 2.12g of Pb(N03)2?

I tried working out the number of moles by saying moles= mass/MR

and did 2.12/2[207.2+2(14+48)]

Which gave me 3.2x10^-3 mol?

Then n=v/24 so v= 24*(3.2x10^3)

The answer is wrong lmao. So I have messed up big time. Anyone care to help me with understanding what is wrong? Thanks :smile:

Reply 1

Farseer

Pb(NO₃)₂ is the solid which decomposes into other gases and another solid PbO

the number of moles of Pb(NO₃)₂ it is not equal to the moles of gas produced - use the chemical equation to determine this