Copper will react with sulfur to form a copper sulfide. If 1.500g copper reacts with sulfur to form 1.880g of copper sulfide, what is the empirical formula of the copper sulfide?
This Site Might Help You. RE: What is the empirical formula of the copper sulfide? Copper will react with sulfur to form a copper sulfide. If 1.500g copper reacts with sulfur to form 1.880g of copper sulfide, what is the empirical formula of the copper sulfide?
The other answerer to this problem is incorrect. Copper comes in 2 ion states, Cu+ and Cu++. You need to determine which one this is. The other answerer never determined, and simply guessed. To do so, calculate the moles of each using the molar masses of Copper and Sulfur. 1.500 g Cu = .024 moles Cu (Molar mass Cu = 63.6 g/mol) Since the compound is only Cu and S, you know that there are .380g S in the compound. .380 g S/32.0 = .012 moles S (Molar mass S = 32.0 g/mol) So there are 2 moles Cu for every mole S. The empirical formula for the compound is Cu2S. The name is Copper (I) Sulfide.
It could be either Cu2S (cuprous sulphide) or CuS (copper(II)sulphide. the amount of sulphur is not specified, so if its a writtn question, I would mention this fact. If sulphur is limitting, it is CuS Thats why we use the roman numeral system, to avoid the confusion.
It can be either CuS or Cu2S since the quantity of S is not specified. If sulphur is a limiting reagent, then is will be CuS. If sulphur is in excess, then is it Cu2S. To claim it must be one or the other is just naive. CuS is copper sulphide or copper(II)sulphide Cu2S is cuprous sulphide or copper(I)sulphide To demonstrate that it can be either: Cu(s) +S(s) --> CuS 1.880 g (0.0197 mol) CuS is produced so 0.0197 mol each of Cu and of S reacted. mass Cu reacted (0.0197g x 63.546 g/mol) = 1.252g 0.248g Cu remains unreacted mass S reacted (0.0197g x 32.065 g/mol) = 0.632g The product copper(II)sulphide is CuS Sulphur is the limiting reactant. ALTERNATIVELY, 2Cu + S --> Cu2S 1.880 g Cu2S is 0.0118 mol so 0.0236 mol (1.500g) Cu reacted and 0.0118 mol (0.378g) S reacted The product is copper(I)sulphide So both calculations work! since the quantity of sulphur was not given, we could not know which applied, except that the name of the product was indicated, copper sulphide, but not the oxidation state. At a higher level chemistry (questioner does not give his/her level) you would be expected to give this answer or something similar. If you are only at an elementary level in your studies, then you will probably jump at the first answer that occurs to you and assume that it is the only correct answer.
