Related Questions for Experiment 12 1. In most fatal cases of aspirin poisoning, the dosage has been many aspirin tablets are necessary to supply 20 grams of aspirin? Calculations: 2. The toxicity of a substance is usually given in the form "LD (method of dosage) in (lest specie): x mg/kg (of body weight)." For example, for salicylic acid, The Merck Index gives: LD so i.v. in mice: 500 mg/kg. "I.v." means intravenous, by injection into a vein. The LDo must be known when prescribing medicines; to be effective, their doses often have to approach levels at which they may become toxic, and the physician has.t kw whar' ta level is. If salicylic acid toxicity were the same for humans as for mice and a person weighs 132 lbs, what percentage would a 10 g dose be of the LDso dose? (Show your calculations.) 3. Why do the textures of different brands of aspirin tablets differ? Aspirin relieves the symptoms of head colds by reducing fever and casing aches and pains but does not shorten the time needed to "get over" the cold. Some physicians have suggested that aspirin may actually lengthen the period of a cold. Why might aspirin have this lengthening effect? 4.