Question

an epipen is an epinephrine autoinjector for anaphylaxis. what is the mass percentage of 6.0 g of epinephrine in 285 g of solution, to the tenths place?

• your answer should have two significant figures.

Explanation:

Step1: Write the formula for mass percentage

Mass percentage = $\frac{\text{mass of solute}}{\text{mass of solution}}\times100\%$

Step2: Substitute the given values

Here, mass of solute (epinephrine) = $6.0\ g$ and mass of solution = $285\ g$.
So, mass percentage = $\frac{6.0}{285}\times100\%$

Step3: Calculate the value

$\frac{6.0}{285}\times100\%=\frac{600}{285}\% \approx 2.105\%$

Step4: Round to the tenths place and two significant figures

Rounding $2.105\%$ to the tenths place and two significant figures gives $2.1\%$

Answer:

$2.1\%$