An acetaminophen suspension for infants contains 80 mg/0.80 mL suspension. The recommended dose is 15 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 14 lb? (Assume two significant figures.)

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Hi, everyone. Welcome back. Our next problem says an acetaminophen suspension for infants contains 80 mg per 0.80 mL of suspension. The recommended dose is 15 mg per kilogram of body weight. How many milliliters of a suspension should be given to an infant weighing £14. Assume two significant figures. A 0.80 mL. B 1.50 mL, C 1.07 mL or D 0.95 mL. Well, one thing to note is that two of our answer choices can be ruled out right away because our problem tells us to assume two significant figures. So choice B 1.50 mL and choice C 1.07 mL each have three significant figures or three sig figs. So that's not going to be our answer since it goes right against what it tells us in the problem. So just a little note there to sort of weed down your numbers of answer possibilities. So this is an example of a problem where a well set up set of conversion factors can bring us from what we start with to what we need. All sort of in one, almost one big long step. So we have to sort of think through our plan of where we'll go here. So we're starting with the wheat of the infant in pounds, but we need that weight to be in kilograms. So we'll need to convert that to weight in kilograms. Then we have the dosage in milligrams per kilogram. So we want to go to the dose or the amount given in milligrams And then we can go from there our dose in milligrams to a dose in milliliters. And that is what we're looking for. Since our question says, how many milliliters of the suspension should be given? So let's set up our series of conversion factors. We start with £14 for our infant. Now we need to convert that to kilograms. So we just look at the conversion there and we can look up that it's £2.205 per kilogram. So we need pounds to cancel out. So when we write our conversion factor, we put £2.205 on the bottom of that fraction, the denominator and the numerator will be 1 kg. So that will take us from pounds to kilograms of body weight. So we'll multiply again to use our conversion factor to get 2 mg of the acetaminophen. So we have 15 mg per kilogram. So let's draw a line here. We want to go from cancel out the kilograms of body weight. So 1 kg in the denominator and 15 mg, we'll put milligrams of 8 mg of acetaminophen. And then last of all, we need to go from milligrams of acetaminophen to milliliters. So multiply again, draw wine there and we have that there's 80 mg of acetaminophen per 0.80 mL. So I'll put 80 mg of A in the denominator and then zero point 8 0 mL in the numerator. So there we have it, we've gone all the way from pounds to milliliters. Put an equal sign, double check that our units come out, right? So in the first step, we have pounds canceling out. And a second step, kilograms canceling out third step milligrams of Camin ofen canceling out. And what's left at the end is milliliters, which is what I'm looking for. So then I'll just do this math here. So it will end up being 14, divided by 2.205 multiplied by 15, multiplied by 0.80 divided by 80. So that's how we end up plugging in those numbers. We do that. We end up getting as our final answer, zero point 95 2 4 mL. Now we were told to assume two significant figures. So our answer will end up being the 0.95 mL, which as we see is choice D. So again, as we were given this various pieces of information, we needed to go from the weight of our infant to how many milliliters of suspension we needed? And we get choice D 0.95 mL. See you in the next video.

An acetaminophen suspension for infants contains 80 mg/0.80 mL suspension. The recommended dose is 15 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 14 lb? (Assume two significant figures.)

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Key Concepts

Dosage Calculation

Unit Conversion

Concentration of Suspension