Question

Question #e1a77

Answer 1

Answer is 286g (3s.f)

Explanation:

Concept required: mole calculation

First start off by finding the number of moles for both compounds:
PbCl(OH)=`0.185/(207.2+35.5+16+1)*1000` (1kg=1000g) = 0.712(to 3s.f)
Pb2Cl2CO3=`0.185/(207.2*2+35.5*2+12+16*3)*1000` = 0.339(to 3s.f)

Next, find the moles of Pb from each compound:
Pb : PbCl(OH)
1 : 1
Therefore, moles of Pb in PbCl(OH) is 0.712
Pb : Pb2Cl2CO3
2 : 1
Therefore, moles of Pb in Pb2Cl2CO3 is `2*0.339 = 0.678`

Now find the total mass of Pb:
`(0.678+0.712)*207.2 = 288g`