Question

the density of ethanol, a colorless liquid that is commonly known as grain alcohol, is 0.798 $\frac{g}{ml}$. calculate the mass of 32.2 ml of the liquid in grams. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Recall density formula

Density $
ho=\frac{m}{V}$, where $m$ is mass and $V$ is volume. We can re - arrange it to solve for mass: $m =
ho\times V$.

Step2: Substitute given values

Given $
ho = 0.798\frac{g}{mL}$ and $V=32.2\ mL$. Then $m=0.798\frac{g}{mL}\times32.2\ mL$.

Step3: Calculate the mass

$m = 0.798\times32.2=25.7956\ g$.

Step4: Determine significant digits

The least number of significant digits in the values used in the calculation is 3 (in 0.798 and 32.2). Rounding 25.7956 to 3 significant digits gives $m = 25.8\ g$.

Answer:

$25.8$