The only compound containing copper in an ore is chalcopyrite,CuFeS₂.If a 90.0 g-sample of this ore contains 22.0 % of copper,what is the percentage of CuFeS₂ in the sample? A) 24.4% B) 6.86% C) 0.635% D) 57.2% E) 42.8%

Question

Quizplus · Accepted Answer

The percentage of CuFeS2 in the sample can be calculated as follows:% CuFeS2 = (mass of CuFeS2 / mass of sample) x 100%The mass of CuFeS2 can be calculated as follows:mass of CuFeS2 = (mass of copper / % of copper in CuFeS2) x molecular weight of CuFeS2The % of copper in CuFeS2 is 34.6%.The molecular weight of CuFeS2 is 183.5 g/mol.Therefore, the mass of CuFeS2 is:mass of CuFeS2 = (22.0 g / 0.346) x 183.5 g/mol = 114.4 gThe percentage of CuFeS2 in the sample is:% CuFeS2 = (114.4 g / 90.0 g) x 100% = 57.2%Therefore, the correct answer is D) 57.2%.

The Only Compound Containing Copper in an Ore Is Chalcopyrite,CuFeS2

The Only Compound Containing Copper in an Ore Is Chalcopyrite,CuFeS₂