Question

a 15.0 ml urine sample from a dehydrated patient has a density of 1.019 g/ml. what is the mass of the sample, reported in mg?
15.3 mg
67.9 mg
6.79 × 10⁻⁵ mg
1.53 × 10⁴ mg
1.47 × 10⁴ mg

Explanation:

Step1: Recall the formula for density

Density ($
ho$) is given by the formula $
ho = \frac{m}{V}$, where $m$ is mass and $V$ is volume. We need to find the mass $m$, so we can rearrange the formula to $m =
ho \times V$.

Step2: Identify the given values

The density $
ho = 1.019\ \text{g/mL}$ and the volume $V = 15.0\ \text{mL}$.

Step3: Calculate the mass in grams

Substitute the values into the formula: $m = 1.019\ \text{g/mL} \times 15.0\ \text{mL} = 15.285\ \text{g}$.

Step4: Convert grams to milligrams

We know that $1\ \text{g} = 1000\ \text{mg}$, so to convert grams to milligrams, we multiply by 1000: $15.285\ \text{g} \times 1000\ \text{mg/g} = 15285\ \text{mg} = 1.53 \times 10^4\ \text{mg}$ (rounded to three significant figures).

Answer:

$1.53 \times 10^4$ mg (corresponding to the option "1.53 × 10⁴ mg")