How much chalcopyrite had to be mined to produce 100 pennies if reaction 1 had a percent yield of 63.00 % and all other reaction steps had yield of 100%?

1) Balanced chemical reaction 1:

2CuFeS₂ + 3O₂ → 2CuS + 2FeO + 2SO₂.  

Balanced chemical reaction 2: 2FeO + SiO₂ → 2FeSiO₃.  

Balanced chemical reaction 3: 2CuS → Cu₂S + S.

Balanced chemical reaction 4: Cu₂S + S + O₂ → 2Cu + 2SO₂.

m(Cu) = 3.0 g; mass of copper in one penny.  

n(Cu) = m(Cu) ÷ M(Cu).

n(Cu) = 3 g ÷ 63.55 g/mol.

n(Cu) = 0.047 mol; amount of copper in one penny.

2) From balanced chemical reactions: n(Cu) : n(CuFeS₂) = 1 : 1.

n(CuFeS₂) = 0.047 mol.

ω(CuFeS₂) = 63.00% ÷ 100%.

ω(CuFeS₂) = 0.630; a percent yield of chemical reaction 1.

m(CuFeS₂) = 0.047 mol · 183.54 g/mol ÷ 0.630.

m(CuFeS₂) = 13.692 g; mass of chalcopyrite for one penny.

m(CuFeS₂) = 13.6927 g · 100.

m(CuFeS₂) = 1369.27 g; mass of chalcopyrite for 100 pennies.

the dependant variable is spilled water

the independent is the heat

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.