A-level physics tomorrow. Please help me with this question(s): Copper is extracted from its ore, copper pyrite. The ore is roasted in a limited supply of oxygen. The following equations describe the process: 1. 2CuFeS2 (s) + 4O2 (g) ---> CuS2 (s) + 3SO2 (g) + 2FeO (s) 2. Cu2S (s) + O2 (g) ---> 2Cu (s) + SO2 (g) a. (i) Calculate the number of moles of CuFeS2 in 200g. (ii) In the experiment 88g of Cu2S is produced from 200g of copper pyrite as per equation 1. Calculate the mass of Cu produced from 200g of copper pyrite. (iii) Calculate the percentage of Cu in copper pyrite. Please help me with these questions. Question (i) I can do, but don't know how to do the rest. Thank you!
Copper is extracted from its ore, copper pyrite. The ore is roasted in a limited supply of oxygen. The following equations describe the process: Since the amount of oxygen is limited, we need to determine the amount of oxygen which was needed for the second reaction. 2. Cu2S (s) + O2 (g) ---> 2Cu (s) + SO2 (g) The coefficients in the balanced equation determine the ratio of moles of reactants and moles of products. 1 mole of Cu2S reacts with 1 mole of O2 to produce 2 moles of Cu and 1 mole of SO2. Let’s determine the number of moles of Cu2S. For Cu2S, mass of 1 mole = 63.5 + 2 * 32.1 = 127.7 g; Moles of CuS2 = 88/127.7 Ratio of moles of O2 to moles of Cu2S = 2 : 1 Number of moles of O2 = 2 * 88/127.7 = 176/127.7 Ratio of moles of Cu to Cu2S = 1 : 2 Number of moles of Cu = ? * 88/127.7 = 44/127.7 We need 44/127.7 moles of Cu from the first reaction! Ratio of moles of SO2 to Cu2S = 1 : 1 Number of moles of SO2 = 88/127.7 We need 88/127.7 moles of SO2 from the first reaction! Let’s determine the number of moles of O2 in the SO2 1 mole of SO2 contains 2 moles of O2 Number of moles of O2 = 2 * 88/127.7 = 176/127.7 Total number of moles O2 needed for the second reaction = 176/127.7 + 176/127.7 = 352/127.6 I am still working!
