Question

A chemist weighed out 101. g of potassium. Calculate the number of moles of potassium she weighed out.

Round your answer to 3 significant digits.

Answer 1

101 g of Potassium is equivalent to 2.583 moles of Potassium.

Explanation:

As per definition of moles, molecular weight of a substance = 1 mole

So molecular weight of Potassium = 39.0983 g

∵ 39.0983 g weight of Potassium = 1 mole

∴ 1 g weight of Potassium =
`(1)/(39.0983)` g

∴ 101 g of Potassium =
`(101)/(39.0983)` g

= 2.583 moles

Therefore, 101 g of Potassium is equivalent to 2.583 moles of Potassium.

Answer 2

The answer is 2.58 moles potassium
The solution to this is,
to find moles, convert grams to mole by the equation
grams(mole/gram)=moles
101. g of potassium(1 mole potassium/39.10 g potassium)=2.58 moles potassium