What is the mass of a metal sample with a volume of 8.6 mL and a density of 7.7 g/mL? Include units and one decimal place in answer.

Question

How do I set this equation up?

Answer 1

To set ip the “equation “, you have ...

8.6 ml x 7.7 g/ml = 66.22 g = 66.2 g (to q decimal place). But, it should really be to 2 significant figures which would be 66 g

Answer 2

This is all about unit conversion.

Since mL are mentioned in both, you know that those go together in some way. We know that the answer is supposed to be just mass (grams), so the mL have to cancel out. So, if we multiply 8.6 mL and 7.7 g/mL, the mL will cancel and leave you with the answer: 66.22 grams, but because of significant figures, we know it should be 66 g.