Answer to Question #97167 in General Chemistry for Shawnster

Question

what is mole?

Answer 1

In general, mole is a unit for measuring the amount of substance.

We know how to measure mass. For example we can take 1 kg of sugar and 1 kg of cotton. Both will have the same mass but the volume of cotton will be bigger and the amount of cotton particles will be much higher than the amount of sugar particles. The same situation with volume. 1L jar of water and 1L jar of air will have different mass and different number of particles in a jar.

1 mole of a substance contains 6.022 140 76 × 10²³ elementary entities (molecules, atoms etc). the number 6.022 140 76 × 10²³ is called Avogadro number (N_A). 1 mole of 2 different substances will have different mass and different volume but will contain the same amount of particles (exactly 6.022 140 76 × 10²³). Difference in mass and volume occurs because the size of particles differs: 1 mole of Helium is made up with 6.022 140 76 × 10²³ small atoms while 1 mole of sugar is made up with the same amount but of the bigger molecules of glucose.