Question

4. You are asked to make 125 grams of a 7% antifungal cream using tolnaftate powder and Eucerin cream. How many grams of tolnaftate powder are needed? Round to the nearest hundredths (w/w)

Answer 1

Answer:

8.75 g

Explanation:

The mass of tolnaftate must be 7 % of the total mass.

Mass = 0.07 × 125 g = 8.75 g

You need to use 8.75 g of tolnaftate powder.

Answer 2

Answer:

8.75 grams of tolnaftate powder is needed.

Explanation:

Mass by mass percentage (w/w) % : It is the percentage of solute present in 100 grams of solution.

$(w/w)\%=\frac{\text{Weight of solute}}{\text{Weight of the solution}}$

Given mass of the solution = 125 g

Mass of the solute required = x

Mass by mass percentage of the solution = 7%

$7\%=\frac{x}{125 g}\times 100$

$x=\frac{7\times 125 g}{100}=8.75 g$

8.75 grams of tolnaftate powder is needed.