Question

A chemist mixes 28.5 g of water with 95.6 g of acetic acid and 24.0 g of acetone. Calculate the percent by mass of each component of the solution T-shirt each of your answers entries has the correct number of significant digits component: water mass %?Acetic acid mass %?Acetone mass %?

Answer 1

We have to know first the total mass of the solution, so we sum all the mass given:

Water: 28.5 g

Acetic acid: 95.6 g

Acetone: 24 g

Total mass: 28.5 g + 95.6 g + 24 g = 148.1 g

Now, the percent by mass is defined like:

$\text{Percent by mass = }\frac{\text{Mass of solute}}{\text{Mass of solution}}\times100$

Then we divide each solute by the total mass of the solution and multiply by 100:

Water:

$\frac{28.5g}{148.1g}=19.2$

Acetic acid:

$\frac{95.6g}{148.1g}=64.6$

Acetone:

$\frac{24g}{148.1g}=16.2$

So, the answer will be:

Water mass 19.2%

Acetic acid mass 64.6%

Acetone mass 16.2%