Chemistry help? Any help would be appreciated, even if just equation setups. I looked in the merck index and online like it said, but couldn't find it.

Question

1.) Look in the Merck index or online to find the toxicity of oil of wintergreen (methyl salicylate) for rats, in mg/kg of body mass.

2.) How many grams of methyl salicylate would you personally have to eat to receive a toxic dose?

a.) What is your mass in kg? (Mine is 25)

b.) Based on this mass, what is the predicted lethal dose?

3.) A common rubbing ointment contains 30% methyl salicylate. How many grams of ointment would you have to accidentally ingest to receive a lethal dose of methyl salicylate?

Answer 1

1.) I found an LD50 for methyl salicylate of 887 mg/kg for rats. It isn't from the Merck and I can send you the reference if you wish.

2). This is silly because in part 1, they ask you for the toxicity in rats, and then here they ask about toxicity in you (a human). If we extrapolate from rats to humans, then...

(a) 25 kg means you weigh only 55 pounds. Are you sure this is correct. Assuming it is, then...

(b) 25 kg x 887 mg/kg = 22,175 mg = 22.2 grams

3.) 30% (w/w) means 30 g of methyl salicylate per 100 g of ointment. This converts to 0.30 g M.S./ g ointment

(0.30 g MS/g ointments )(x g ointment) = 22.2 g and x = 74 g ointment would have to be ingested.

Answer 2

I found an LD50 for methyl salicylate of 887 mg/kg for rats (http://www.inchem.org/documents/jecfa/jecmono/v44aje28.htm). This isn't the Merck but it'll have to do.

2). This is silly because in part 1, they ask you for the toxicity in rats, and then here they ask about toxicity in you (a human). If we extrapolate from rats to humans, then...

(a) 25 kg means you weigh only 55 pounds. Are you sure this is correct. Assuming it is, then...

(b) 25 kg x 887 mg/kg = 22,175 mg = 22.2 grams

3.) 30% (w/w) means 30 g of methyl salicylate per 100 g of ointment. This converts to 0.30 g M.S./ g ointment

(0.30 g MS/g ointments )(x g ointment) = 22.2 g and x = 74 g ointment would have to be ingested.