One of the more important topics in introductory chemistry that will be needed in all future chemistry is molar conversion. What molar conversion is, is basically converting between the different measuring units that can make up the mole. Recall, the mole is a measurement unit similar to a dozen of items or bundle of sticks (with a number), that 1 mole would equal to a gigantic number of 6.023 x 1023 things. In addition, the mole can also be converted to the following:
1st The mole can be used to found the number of things, particles, molecules, zombies, ions, cars, dollars, babies, fish, etc… you get the point.
1 mole would have 6.023 x 1023 of each of them.
2nd The mole can be used to calculate the amount of mass of each element. This one could be tricky because each element has different atomic masses dependent on size even though they all have 1 mole. The atomic masses found on the Periodic Table are all showing the mass for 1 mole. For example, 1 mole of Hydrogen, 1 mole of Calcium, 1 mole of Iron all have different masses, 1.00 g/mol, 40.0g/mol, 55.545g/mol respectively.
3rd The third conversion involves the amount of gas molecules found in gases and gases only. Experiments have showed that in a closed fixed container of 22.4L, 1 mole of gas molecules will exist. In other words, 1 mole of gas molecules will be found in a 22.4L closed container regardless of the type of gas. The gas could be oxygen gas, chlorine gas, CO2 gas or methane gas, if there is 1 mole of gas, it will have a volume of 22.4L.
So what can you do with all of this?
All three of the above measuring units (particles, mass, and volume of gas) can be converted interchangeably but only if moles are found first!
An analogy of molar conversion is similar to this:
Imagine if you were to go traveling and you went to 3 different countries: Japan, Ghana, and Malaysia. All three of the above countries use different currencies but in order to make sense of how much each currency is worth, you have to convert it back to something that you know and that is Canadian dollars (or your current currency).
So first, you travel to Japan. The exchange rate is 100 Yen = 1 Canadian dollar. You buy something that is 2000 Yen. In order to make sense of how much you are spending, you have to convert the 2000 Yen into Canadian dollars, 2000 / 100 = $20 Canadian dollars.
Now you travel to Ghana where the conversion rate is 1.5Cedis = $1 Canadian dollar. A friend from Ghana asks you how much you paid for the item you bought in Japan. In order to tell your Ghanaian friend, you must convert the Japanese Yen into Canadian dollar and then convert it back to Ghanaian Cedi. There is no direct conversion from Yen to Cedi (unless you derive a formula). Likewise with going to Malaysia, you would have to convert the Malaysian Ringgits to Canadian dollar first before converting it into any other currency.
Molar conversion is exactly the same as the analogy that the mole is your central unit, the Canadian dollar. You have to first convert everything into moles then convert into any of the other 3 units.
- Calculating average atomic mass and what that means.
- Importance and applications of isotopes
- Know how to name covalent/ionic compounds with polyatomic ions and multivalent elements.
- Know how to balance chemical reactions
- Be able to describe the concept of the mole and its importance to measurement in chemistry.
- Mole conversions (Molar volume, mass, and particles)
- Know how to identify the type of reaction and be able to predict products and reactants.
- Know how to use mol-mol ratio to calculate moles of another or mass of another
- Calculate your limiting reagent and excess
- Know how to determine your empirical formulas from percent composition