Question

What is the density of a substance with a mass of 45.00g and volume of 26.4 ml?

Answer 1

Approx. `2` `g*mL^-1`

Explanation:

`"Density, "rho="Mass"/"Volume"` `=` `(45.00*g)/(26.4*mL)` `=` `??*g*mL`.

I acknowledge that we are making a meal out of the problem if we include the units this way. Physical scientists persist in this practice because it introduces an extra check on their numerical calculations. We were asked to find the density, and we got an answer in `g*mL^-1`, which is dimensionally reasonable.

It is all too easy to mulitply instead of divide and get an answer in `mL*g^-1` or `"furlongs per fortnight"`.