The iodide ion, usually consumed as potassium iodide, is a dietary mineral essential to good nutrition. in countries where potassium iodide is added to salt, iodine deficiency or goiter has been almost completely eliminated. the recommended daily allowance (rda) for iodine as 150 micrograms per day. how much potassium iodide (76.45% i) should you consume to meet the rda?

196 micrograms of potassium iodide per day

Explanation:

The question tell us that the requirement is 150 micrograms of iodine a day. Eating 150 micrograms of potassium iodide would not help because iodine would only be 76.45% of that sample. So we need to find a mass m, for which 76.45% is 150 micrograms:

m = 196 micrograms of potassium iodide

the answer is d. 74.02

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2