Chemical Reaction: How Much Copper is Left Over?

How much copper is left over after a student heats 3.55 grams of copper and 4.60 grams of iodine for 6.25 grams of a new compound?

The question involves the concept of material balance in a chemical reaction. The key idea here is that the amount of substance used in the reaction should be equal to the amount of substance after the reaction occurs. Let's break down the data given:

Amount of copper used = 3.55 grams

Amount of iodine used = 4.60 grams

Total amount of reactants = 3.55 grams + 4.60 grams = 8.15 grams

Amount of product formed = 6.25 grams

Since all the iodine reacted in the reaction, but there is still some copper left unused, we can calculate the amount of copper left over:

8.15 grams (total reactants) - 6.25 grams (product formed) = 1.9 grams of copper left over

Therefore, the amount of copper left over after the reaction is 1.9 grams.

Understanding Material Balance in Chemical Reactions

Material balance is a fundamental concept in chemistry that ensures the conservation of mass in a chemical reaction. According to this principle, the total mass of substances before the reaction must be equal to the total mass of substances after the reaction.

In the given scenario, we are provided with the amounts of copper and iodine used in the reaction, as well as the amount of product formed. By applying material balance, we can determine how much copper is left over after the reaction.

First, we calculate the total amount of reactants, which is the sum of the masses of copper and iodine used. This gives us 8.15 grams.

Next, we compare the total amount of reactants with the amount of product formed. Since not all the copper reacted and there is some left over, we subtract the mass of the product from the total mass of reactants to find the amount of copper left over, which is 1.9 grams.

By understanding and applying the concept of material balance, we can accurately determine the amount of substances involved in a chemical reaction, highlighting the conservation of mass in the process.

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