Determining the Leftover Copper in a Chemical Reaction

How much copper is left unreacted at the end of the reaction?

The mass of copper that is left unreacted at the end of the chemical reaction is 1.90 g. What mass of copper is left unreacted at the end of the reaction?

The Amount of Leftover Copper in the Reaction

The mass of copper left unreacted in the chemical reaction can be calculated based on the initial masses of copper and iodine and the mass of the product formed.

When a student heats 3.55 g of copper and 4.60 g of iodine, a new compound is formed weighing 6.25 g. This reaction indicates that all of the iodine reacted, but there is some copper left unused.

According to the law of conservation of mass, the total mass of reactants should be equal to the total mass of products and any unreacted material. In this case:

Mass of copper before the reaction = 3.55 g

Mass of iodine before the reaction = 4.60 g

Mass of product formed = 6.25 g

Therefore, the total mass of reactants is calculated as:

Mass of reactants = 3.55 g + 4.60 g = 8.15 g

The mass of unreacted copper can be determined by finding the difference between the total mass of reactants and the mass of the product formed:

Mass of unreacted copper = 8.15 g - 6.25 g = 1.90 g

This means that 1.90 g of copper is left unreacted at the end of the chemical reaction. The leftover copper indicates that not all of it reacted to form the compound, leaving some unused.