Question

If one mole of acetone has a mass of 58.1 g, what is the mass of 0.015 millimoles (mmol) of the acetone? express your answer in nanograms using the correct number of significant figures.

Answer 1

1 mole of acetone has a mass of 58.1 g thus, molar mass of acetone is 58.1 g/mol. Number of mole can be converted into mass as follows:

$m=n\times M$ ...... (1)

Here, n is number of mole, m is mass and M is molar mass.

First convert milimole to mole as follows:

$1 mmol=10^{-3}mole$

Thus,

$0.015 mmol=0.015\times 10^{-3} mol=1.5\times 10^{-5} mol$

Putting the values in equation (1)

$m=n\times M=1.5\times 10^{-5}mol\times 58.1 g/mol=8.71\times 10^{-4}g$

Converting grams into nano grams:

$1 g=10^{9}nanogram$

Thus,

$8.71\times 10^{-4}g=8.71\times 10^{-4}\times 10^{9} g=8.71\times 10^{5} nanograms$

Thus, the mass of acetone is $8.71\times 10^{5}$ nano grams.