If your percent yield of copper were greater than 100%, what are two plausible errors you may have made

1) The sample may not have been dried properly

2) presence of other impurities in the copper

Explanation:

When the sample is not properly dried, water molecules remain attached to the sample and when the sample is weighed, its weight will be higher than it should be due  to the water molecules present. This will make the percentage yield of copper to exceed 100%.

Other impurities present in the copper may make it to weigh higher than it should thereby raising the percent yield of copper above 100%.

hey there!

boiling point is the temperature at which the vapor pressure of the liquid equals atmospheric pressure. the vapor pressure of solvent molecules is decreased when a solute is added, so a higher temperature is required to increase the number of solvent molecules in the gas phase above the liquid.

at the freezing point, the vapor pressures of the solid and liquid are equal; a lower temperature is needed to reduce the number of solvent particles above the liquid.

hope this you

tobey

i'm pretty sure it is letter c.) car