Benadryl is used to treat itchy skin in dogs. the recommended dosage is 1 mg per pound. what mass of benadryl, in milligrams, should be given to a dog that weighs 29.5 kg?

65 mg

Explanation:

We are given the dosage per pound but have the weight of the dog in kilograms, thus we should convert the 29.5 kg to punds ( 1 pound = 0.454 kg):

29.5 kg  x 1 lb / 0.454 kg = 64.7 lbs

So now can answer our question:

( 1 mg / lb ) x 64.7 lb = 64.7

rounding to 65 mg

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g