Assume the copper was not thoroughly dried. How will the following calculations be affected?
The calculated mass of copper will be too low or too high?
The calculated moles of copper will be too low or too high?
The calculated mass of chlorine will be too low or too high?
The calculated moles of chlorine will be too low or too high?
The answer should be A, I could be wrong though. Water seeps into any open crack or pore, making something denser, therefore could cause more (or less) mass.
