The Abbreviated Method of Writing Mole Is Mol

The Mole

Mole is a unit of measurement used in chemistry to express amounts of a chemical substance. The mole is widely used in chemistry instead of units of mass (grams) or volume (liters) as a convenient way to express amounts of reactants or products of chemical reactions. A handy way of thinking about a mole is that it is a very large pile of something (that something is usually incredibly small objects like atoms, molecules, electrons, etc) and this pile has a number associated with it: 6.022 x 1023, a.k.a. “Avagadro’s Number”. Just like you may pick up 4 “dozen” donuts from Tim Horton’s, you may decide to react 4 “moles” of propane in an experiment.

For example, the chemical equation 2 H2 + O2 → 2 H2O implies that 2moles of hydrogen molecules (H2) and 1mole of oxygen molecules (O2) react to form 2moles of water (H2O). (This is actually possible to do, whereas trying to react two molecules with one molecule is just not possible given the ridiculously small size of these molecules). The mole may also be used to express the number of atoms, ions, or other elementary entities in a given sample of any substance. The concentration of a solution is commonly expressed by its molarity, defined as the number of moles of the dissolved substance per liter of solution.

The abbreviated method of writing mole is mol.

Molar Mass

Molar Mass: The mass in grams of one mole of any pure substance. Conveniently, the mass of one mole of Carbon-12 atoms is exactly 12 grams. Therefore, the mass numbers found below the element symbols on the periodic table (given in amu) are also the grams of one mole of the element as found in nature.
For example, one mole of magnesium (Mg) weighs 24.3050 grams while one mole of mercury (Hg) weighs 200.59 grams.
With this knowledge we can find the number of atoms in any element if we know the mass of the element in question. We can not find this by direct conversion, but use Avagadro’s number (6.022 x 1023), the mole, as the go-between from grams to atoms (or atoms to grams).
Example: How many atoms of copper do you have if you possess 196 grams of copper wire?
196 g Cu x1 mole Cu x6.022 x 1023 atoms = 1.86 x 1024 atoms of copper.
63.546 g 1 mole
Example: How many grams of aluminum do you have if you possess 1.55 x 1024 atoms?
1.55 x 1024 atoms x ____1 mole ______x_26.98 g Al = 69.4 g aluminum.
6.022 x 1023 atoms 1 mole
Example: How many kilograms of silicon do you have if you are holding 3.87 x 1026 atoms of silicon?
3.87 x 1026atoms x ____1 mole _____x_28.085 g Si x 1 kg = 18.0kg silicon
6.022 x 1023 atoms 1 mole 1000 g

Moles, Molecules, and Grams Worksheet

1)How many moles are there in 99 grams of Fe?

2)How many atoms are there in 452 grams of Na?

3)How many grams are there in 2.3 x 1024 atoms of silver?

4)How many moles are there in 7.4 x 1023 atoms of N?

5)How many grams are there in 7.5 x 1023 atoms of K?

6)How many moles are there in 122 grams of Cu?

7)How many grams are there in 9.4 x 1025 atoms of Kr?

8)How many atoms are there in 237 grams of Co?

9)How many atoms are there in 2.3 grams of Sr?

10)How many grams are there in 3.3 x 1023 atoms of Ru?

11)How many atoms are there in 2003 grams of W?

12)How many grams are there in 1.3 x 1024 atoms of B?

13)How many grams are there in 4.5 x 1022 atoms of Ba?

14)How many moles are there in 9.34 grams of Mn?

15)How many grams do 4.3 x 1021atoms of U weigh?

16)How many atoms are there in 234 grams of Ni?

Molar Mass Worksheet

Calculate the molar masses of the following chemicals:

1)KOH

2)BeCl2

3)FeCl3

4)CCl2F2

5)Mg(OH)2

6) UF6

7)SO2

8)(NH4)2SO4

9)Pb(NO3)2

10)Ga2(SO3)3

Molar Mass Worksheet – Answer Key

Calculate the molar masses of the following chemicals

1)KOH 56.1 g/mol

2)BeCl2 80 g/mol

3)FeCl3 162.3 g/mol

4)CCl2F2 121 g/mol

5)Mg(OH)2 58.3 g/mol

6)UF6 352 g/mol

7)SO2 64.1 g/mol

8)(NH4)2SO4 132.1 g/mol

9)Pb(NO3)2 331.2 g/mol

10)Ga2(SO3)3 379.7 g/mol

Given the following, find the number of moles:

1)30 grams of H3PO4

2)25 grams of HF

3)110 grams of NaHCO3

Given the following, find the number of grams:

4)4 moles of Cu(CN)2

5)5.6 moles of C6H6

6)21.3 moles of BaCO3

Putting it all together

7)How many molecules are there in 450 grams of Na2SO4?

8) How many grams are there in 7.4 x 1023 molecules of AgNO3?

Grams/Moles Calculations – Answer Key

Given the following, find the number of moles:

1)30 grams of H3PO4 0.31 moles

2)25 grams of HF 1.25 moles

3)110 grams of NaHCO3 1.31 moles

Given the following, find the number of grams:

4)4 moles of Cu(CN)2 462 grams

5)5.6 moles of C6H6 436.8 grams

6)21.3 moles of BaCO3 4202.5 grams

7)How many molecules are there in 450 grams of Na2SO4? 1.91 x 1024molecules

8)How many grams are there in 7.4 x 1023 molecules of AgNO3? 209 grams

Moles, Molecules, and Grams Worksheet

1)How many molecules are there in 24 grams of FeF3?

2)How many molecules are there in 450 grams of Na2SO4?

3)How many grams are there in 2.3 x 1024 atoms of silver?

4)How many grams are there in 7.4 x 1023 molecules of AgNO3?

5)How many grams are there in 7.5 x 1023 molecules of H2SO4?

6)How many molecules are there in 122 grams of Cu(NO3)2?

7)How many grams are there in 9.4 x 1025 molecules of H2?

8)How many molecules are there in 230 grams of CoCl2?

9)How many molecules are there in 2.3 grams of NH4SO2?

10)How many grams are there in 3.3 x 1023 molecules of N2I6?

11)How many molecules are there in 200 grams of CCl4?

12)How many grams are there in 1 x 1024 molecules of BCl3?

13)How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2?

14)How many molecules are there in 9.34 grams of LiCl?

15)How many grams do 4.3 x 1021molecules of UF6 weigh?

16)How many molecules are there in 230 grams of NH4OH?

Moles, Molecules, and Grams Worksheet – Answer Key

1)How many molecules are there in 24 grams of FeF3? 1.28 x 1023 molecules

2)How many molecules are there in 450 grams of Na2SO4? 1.91 x 1024molecules

3)How many grams are there in 2.3 x 1024 atoms of silver? 421 grams

4)How many grams are there in 7.4 x 1023 molecules of AgNO3? 209 grams

5)How many grams are there in 7.5 x 1023 molecules of H2SO4? 122 grams

6)How many molecules are there in 122 grams of Cu(NO3)2? 3.92 x 1023 molecules

7)How many grams are there in 9.4 x 1025 molecules of H2? 312 grams

8)How many molecules are there in 230 grams of CoCl2? 1.07 x 1024 molecules

9)How many molecules are there in 2.3 grams of NH4SO2? 1.69 x 1022 molecules

10)How many grams are there in 3.3 x 1023 molecules of N2I6? 430 grams

11)How many molecules are there in 200 grams of CCl4? 7.82 x 1023 molecules

12)How many grams are there in 1 x 1024 molecules of BCl3? 195 grams

13)How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2? 17.1 grams

14)How many molecules are there in 9.34 grams of LiCl? 1.33 x 1023 molecules

15)How many grams do 4.3 x 1021molecules of UF6 weigh? 2.51 grams

16)How many molecules are there in 230 grams of NH4OH? 3.96 x 1024 molecules