50 POINTS FOR THIS! Copper (Cu) reacts with sulfur (S) to form copper sulfide. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction. At the end of the experiment, there are 15.9 grams of copper sulfide. In this reaction, all of the copper and all of the sulfur react. The scientist then tries to add 13.7 grams of Cu to 3.2 grams of S. There are still 15.9 grams of copper sulfide at the end, but some copper is also left over. In 1-2 sentences, explain how to calculate the amount of remaining copper. Use the law of conservation of mass in the explanation.

first there is only 25 points on here because if you add 50 points to the question divides it by two so that two people can answer so if you want each person to get 50 points or to advertise how much point sis on this quetstion you would instead need to add 100 points to the question- anyways let's answer this question now

Do you know what the Law of Conservation of mass says? Matter is neither created nor destroyed. Therefore, you have started with 12.7 g Cu and 3.2 g S on the left for a total of 15.9 g; therefore, you must obtain 15.9 g of product(s). If Cu2S is the only product there must be 15.9 g Cu2S.