So, we have now started our new unit on the mole! yay!
Before we start, make sure you are comfortable calculating molar mass.
The first type of conversion is particles --> moles
Remember: 6.022 x10^23 particles/mole
Say you want to convert 3.01 x 10 ^24 particles of carbon to moles.
As with unit conversionis, you need the same units in the beginning of the equation, and on the bottom, so they can cancel eachother.
3.01 x 10^24 particles of carbon x 1 mole
______
6.022 x 10^23 particles
If you do the math, that means that there are 5.00 moles of carbon! Make sure you round off to the correct number of significant digits. The least number of sig figs in the equation is 3, therefore the answer should also have 3 sig figs.
Now, converting moles to molecules.
Lets try converting 0.75 moles of CO2 to atoms of oxygen.
Follow the exact same rules as given in the example above. Always follow those rules, these are just different units we are using.
0.75 moles x 6.022 x10^23 molecules
___________________
1 molecule
Once you multiply, you will calculate that the answer is 4.5 x 10^23 molecules CO2
We can also do conversions between moles and grams.
Lets calculate the grams of 2.04 moles of carbon
Use molar mass! The molar mass of Carbon is 12.0 grams/mol
Now lets do the math!
2.04 moles x 12.0 g
_____
1 mole = 24.5 grams of carbon
For compounds, to get the molar mass, just add up all the masses of each atom of each element.
Last but not least, grams to moles!
How about we convert 3.45 grams of carbon back to moles
Remember everything we have done so far! Find the mass of Carbon and plug it in. Then just follow the steps and do the math:
3.45 g x 1 mole
_____
12 grams and all this math = 0.288 moles of carbon
There you have it! How to convert from anything to everything! Hope this helps.
No comments:
Post a Comment