Mole vs Number of Particles
1 mole of chemical substance = 6.02 x 1023 of particles
Avogadro constant = 6.02 x 1023
Example 1
Find the number of atoms in 2.5 mol of gold.
Answer:
Number of atoms
= Number of mole x Avogadro constant
= 2.5 x 6.02 x 1023 = 1.505 x 1024
Find the number of atoms in 2.5 mol of gold.
Answer:
Number of atoms
= Number of mole x Avogadro constant
= 2.5 x 6.02 x 1023 = 1.505 x 1024
Example 2
How many moles of magnesium that contain 2.76 x 1023 of magnesium atom?
Answer:
Number of mole
= Number of atoms ÷ Avogadro constant
= 2.76 x 1023 ÷ 6.02 x 1023
= 0.46 mol
How many moles of magnesium that contain 2.76 x 1023 of magnesium atom?
Answer:
Number of mole
= Number of atoms ÷ Avogadro constant
= 2.76 x 1023 ÷ 6.02 x 1023
= 0.46 mol
Example 3:
a.
Each hydrogen molecules (H2) consist of 2 hydrogen atoms.
Therefore, 20 mol of hydrogen atoms can make 10 mole of hydrogen molecules.
b. Number of mole of hydrogen atoms in 20 mole of hydrogen molecules
= 2 x 20 mole = 40 mole.
- How many hydrogen molecules can be made with 20 mol of hydrogen atoms?
- How many hydrogen atoms are there in 20 mol of hydrogen molecules?
a.
Each hydrogen molecules (H2) consist of 2 hydrogen atoms.
Therefore, 20 mol of hydrogen atoms can make 10 mole of hydrogen molecules.
b. Number of mole of hydrogen atoms in 20 mole of hydrogen molecules
= 2 x 20 mole = 40 mole.
Example 4:
a.
Each carbon dioxide molecules (CO2) consist of 1 carbon atom and 2 oxygen molecules.
Therefore, 0.75 mole of carbon dioxide contain 0.75 mole carbon atoms.
b.
Number of mole of oxygen atoms in 0.75 mole of carbon dioxide
= 2 x 0.75 mole = 1.50 moles.
- Find the number of carbon atom in 0.75 mol of carbon dioxide.
- Find the number of oxygen atom in 0.75 mol of carbon dioxide.
a.
Each carbon dioxide molecules (CO2) consist of 1 carbon atom and 2 oxygen molecules.
Therefore, 0.75 mole of carbon dioxide contain 0.75 mole carbon atoms.
b.
Number of mole of oxygen atoms in 0.75 mole of carbon dioxide
= 2 x 0.75 mole = 1.50 moles.
