Question

A multivitamin tablet contains 40 milligrams of potassium. how many moles of potassium does each tablet contain?

Answer 1

Answer : The moles of potassium is
`1.02* 10^(-3)mol`

Explanation : Given,

Mass of potassium = 40 mg = 0.04 g

conversion used : 1 mg = 0.001 g

Molar mass of potassium = 39 g/mol

Now we have to calculate the moles of potassium.

Formula used :

`\text{Moles of potassium}=\frac{\text{Mass of potassium}}{\text{Molar mass of potassium}}`

Now put all the given values in this formula, we get:

`\text{Moles of potassium}=(0.04g)/(39g/mol)=1.02* 10^(-3)mol`

Therefore, the moles of potassium is
`1.02* 10^(-3)mol`

Answer 2

conversion of mole to grams
k in mole = 1 mole/ atomic mass
K in mole =1/ 39.0983 g/mole
= 0.255765 g/mole
converting 40 grams of K
K 40 grams x [ 1 mole/ 39.0983 grams] = 1.0230623 mole
There are 1.0230623 moles of K in 40 K of Potassium