5. The reaction of hydroiodic acid and potassium hydrogen carbonate produce potassium iodide, which is used as a dietary supplement to prevent the iodine-deficiency disease, goiter. Water and carbon dioxide are by-
products.
HI + KHCO3 → KI + H2O + CO2
a. How many grams of potassium iodide are produced when 481 g of hydroiodic acid and 318 g of
potassium hydrogen carbonate react?

Approximately .

Explanation:

Look up relative atomic mass data on a modern periodic table:

Calculate the formula mass of and (the two reactants,) as well as (the product.)

The question states that while . Calculate the number of moles of formula units in each of these two reactants:

.

.

Note that in the balanced equation of this reaction, the ratio between the coefficients of , , and is .

Therefore, for every mole of formula units consumed, one mole of formula units will also be consumed, while one mole of formula units will be produced.

Similarly, for every mole of formula units consumed, one mole of formula units will also be consumed, while one mole of formula units will be produced.

Assume that is in excess. If all these (approximately) of formula units are consumed, of formula units will also need to be consumed. However, that's not possible because there was only approximately of formula units available.

On the other hand, if is in excess, all these (approximately) moles of formula units would be consumed. At the same time, approximately of would be consumed- which is indeed possible because approximately of formula units are available. Therefore, up to approximately of formula units will be produced.

Calculate the mass of that of formula units:

.