How many moles of Pb Metal would form when the PbCO3 is heated?

Question

There is PbCO3 Pure cerusitte and we are determining how many moles are there there in 7.5g of the starting material..I get 35.6 moles..The next question is .....How many moles of Pb Metal would form when the PbCO3 is heated?

Answer 1

1) How many moles are there in 7.5 gram of PbCO3 ?
1 mol of PbCO3 is 207.2 + 12.01 + 3*16.00 = 267.2 gram
7.5 gram = 7.5 g / 267.2 g/mol = 0.0281 moles.

2) For every molecule of PbCO3 one atom of Pb is formed. There are therefore as many moles of Pb as mole of PbCO3, that is 0.0281 moles.

3) How many grams of lead are formed?
0.0281 moles = 0.0281 moles x 207.2 g/mol = 5.82 g