How do you find the number of moles of a substance

Daily Dose 007 | CHEMISTRY

How do you find the number of moles of a substance?

When hearing the word MOLE makes us think first of a little rascal that digs holes in the backyard, welp, there is some work that we need to do in getting prepared for the FE Exam.

And that’s OK, because moles – in the animal world – can be cute at times! 🙂

In this video, we dive in to a FE Exam Practice Problem, this time in the subject of CHEMISTRY, specifically revolving around determining the NUMBER OF MOLES of a substance in a given sample.

Key Definition

What is a MOLE?

The MOLE is a unit of measurement used in CHEMISTRY.

It measures the amount of pure substances containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12.

However, we don’t use the 12 grams of carbon-12 much on the FE Exam, but rather, AVOGADRO’S NUMBER, which is:

• 1 mol = 6.023e23 particles

Initially, the connotation of MOLE was “gram molecular weight”, however, the usage tends to apply the term MOLE to an amount containing Avogadro’s number of whatever units are being considered. For this reason, it is possible to have a MOLE of atoms, ions, radicals, electrons, particles, or quanta.

In the NCEES Reference Handbook, we see the units of PARTICLES used, but this can in the same way say ATOMS, IONS, etc.

Check out the video and see how we can go about solving this type of problem in the most efficient manner.

As always, with Love, Prepineer

Video Review

How to find the number of moles in a sample