What is the mole (mol)?
The mole is the SI unit for “amount of a substance” and is a unit quantity which refers to how much of an element or compound is present.
We have used other words to represent an understood amount, such as “a couple” meaning 2 or “dozen” meaning 12. Consider the same for the mole. A mole can represent how much or amount of a substance.
Moles and Mass
1 mole of an element is 1 unit of that element:
- 1 mole of carbon is the same as saying 1 unit of carbon or 1 C
- 1 mole of carbon is equivalent to the atomic mass of carbon
- 1 mole of carbon = 12 g of carbon
1 mole of a compound is equivalent to the formula weight of the compound:
- 1 mole of glucose is the same as saying 1 unit of glucose or 1 C6H12O6.
- 1 mole of a compound is equivalent to the formula weight of the compound
- 1 mole of glucose = 180 grams
IMPORTANT NOTE: These equivalencies are conversion factors! You can use dimensional analysis to convert one unit to another like any other simple unit conversion.
Related Bytes: Dimensional analysis and calculating formula weight
Recall the set up of dimensional analysis such that given units are positioned to cancel out!
Let’s try some examples:
1. How many moles are in 144 grams of glucose, C6H12O6?
2. How many grams of NaOH are present in 3.45 moles of NaOH? [Ans: 138]
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