Question

Question #c440b

Answer 1

`"0.12 g"`

Explanation:

Your strategy here will be to use three conversion factors: one to take you from teaspoons to milliliters, one to take you from milliliters to milligrams, and one to take you from milligrams to grams.

The problem tells you that

`color(purple)(bar(ul(|color(white)(a/a)color(black)("1 teaspoon " = " 5 mL")color(white)(a/a)|)))`

Use this to determine the volume of this drug that would be equivalent to `1.2` teaspoons

`1.2 color(red)(cancel(color(black)("teaspoons"))) * "5 mL"/(1color(red)(cancel(color(black)("teaspoon")))) = "6.0 mL"`

Next, the problem tells you that every `"5 mL"` of this drug contains `"100. mg"` of ibuprofen. This means that your sample will contain

`6.0 color(red)(cancel(color(black)("mL drug"))) * "100. mg ibuprofen"/(5color(red)(cancel(color(black)("mL drug")))) = "120 mg ibuprofen"`

Finally, use the fact that

`color(purple)(bar(ul(|color(white)(a/a)color(black)("1 g" = 10^3"mg")color(white)(a/a)|)))`

to find the amount of ibuprofen in grams

`120 color(red)(cancel(color(black)("mg"))) * "1 g"/(10^3color(red)(cancel(color(black)("mg")))) = color(green)(bar(ul(|color(white)(a/a)color(black)("0.12 g")color(white)(a/a)|)))`

I'll leave the answer rounded to two sig figs.