Show how one would set up a ration to determine the mass of a substance given that the density was 5.6g/ml with a volume of 3.7ml. What is the mass?

1 Answer
Oct 19, 2016

#rho("density")="mass"/"volume"#

Explanation:

And thus mass is simply the product:

#"mass"# #=# #"volume "xx" density"#.

For your problem, #"mass"# #=# #5.6*g*cancel(mL^-1)xx3.7*cancel(mL)# #=# #??g#

Note that using the units in the calculation automatically gives the correct units, #"grams"#, for the answer. This is called dimensional analysis, and you can use it as a check on your calculations. It is also too easy to divide when you should have mulitplied, or multiplied when you should divide. Solving a problem dimensionally helps to avoid this.