The Mole

The mole is a unit of measure used in chemistry to show the amount of a chemical substance. One mole is always shown as the equation of 6.02X10²³ or 602 billion trillion. A mole is abbreviated as mol, g/mol.-grams per mole. The number of a mole is always the same only the mass s different.When you are looking for the number of moles in an element for example 1 mol. of antacid Al(OH)3 would equal 78g/mol. this is because the mass of 1 mol of Al is 27, you than look at the other elements 1 mol of O is 16 but if you look at the compound it has Al(OH)3. You take the 3 and multiply it by the 1 mol. of O which gives you 48. You do the same with H and 1X3 which is 3. You than add all of them together 27+48+3=78.  There are other ways to solve a mole. Here are some of them:

1. How many moles are in 15 grams of lithium(Li)
1. to find out you first have to find out how much grams are in one mole of lithium.
1. 7g/mol.
2. Once found you than divide the number of grams so 15 by 7 to get the number of moles which is 2.13g/mol.
2. How many grams are in 2.4 moles of sulfur
1. now this is different we are looking for grams not moles so you really just to the opposite that you did to find moles.
1. there is 32g/mol in 1 mole of Sulfur
2. You than take the 32 and multiply by the number of moles you should get 76.8g/mol.
3. How many moles are in 22 grams of argon
1. 1 mol. Ar=40g/mol
1. 22/40=0.55g/mol
4. How many grams are in 88.1 moles of magnesium
1. 1 mol Mg=24
1. 24*88.1g=2114.4g/mol.
1. *-multiply
2. /-divide
5. Now here are some with compound elements
1. How many grams are in 4.5 moles of sodium fluoride, NaF
1. to solve this you first have to figure out how many grams are in one mole of NaF to do this you find the mass and add them together
1. Na=23g/mol., F=19g/mol.
1. Na+F=42g/mol.
2. taking the 42g/mol you would then multiply by 4.5 to equal 189g/mol.
1. 42*4.5=189g/mol.
2. How many moles are in 98.3 grams of aluminum hydroxide, Al(OH)3
1. Al=27g/mol, O=16*3, H=1*3, than add Al+O+H=78g/mol.
2. divide 98.3 by 78 to equal 1.26g/mol.
1. 98.3/78=1.26g/mol

Hope this post helped you to understand the mole better bye!