The MOLE

Mole (Atoms)

100

1 mol of N₂ = _____ atoms 

1 mol of N₂ = 1.20 x 10²⁴ (3s.f) atoms

 

200

4 mol of CO₂= _____ atoms

4mol of CO₂= 7.22 x 10²⁴ (3 s.f) atoms

300

4.2 mol of H₂O= _____ atoms 

4.2 mol of H₂O= 7.59 x 10²⁴ (3s.f) atoms

400

3.2 mol of H₂SO₄=____ atoms

3.2 mol of H₂SO₄= 1.35 x 10²⁵ (3s.f) atoms

500

2.4 mol of CH₃OH=____atoms 

2.4 mol of CH₃OH= 8.67 x 10²⁴ (3s.f) atoms

Mole (Ions & Molecules)

100

Calculate Number of molecules present in 3 mol of oxygen gas, O₂

no. of molecules = 18.1 x 10²³ (3s.f)

200

Calculate Number of molecules present in 5.6 mol of Nitrogen gas, N₂

no. of molecules = 3.37 x 10²⁴ (3s.f)

300

Calculate Number of H⁺ ions in 3 mol of sulfuric acid, H₂SO₄

no. of H⁺ ions = 3.61 x 10²³ ( 3s.f)

400

Calculate Number of Na⁺ ions in 0.6 mol of sodium carbonate, Na₂CO₃

no. of molecules= 7.22 x 10²³ (3s.f)

500

Calculate Number of H atoms in 7.2mol of cinepazic, C₁₈H₂₄N₂O₆ 

no. of atoms = 1.04 x 10²⁶ (3s.f) 

Molar Mass

100

Calculate Mass of 5 mol of oxygen gas, O_2.

Mass of O₂= no. of mol x molas mass

                = 5 x (16 x 2)

                = 160g 

200

Calculate mass of 15 mol of sodium chloride, NaCl. 

mass of NaCl= 15 x (23+35.5)

                   = 877.5g

300

Calculate number of moles in 441g of water, H₂O.

no. of mol= 24.5 mol

working no. of mol= 441/1(2) +16

                           = 441/18

                           = 24.5 mol

400

calculate number of moles in 25g of calcium carbonate, CaCO₃

no. of mole = 0.250 mol 

working no. of mole= 25/40+12+3(16)

                            = 25/100

                             = 0.250 mol

500

Calculate no. of molecules present in 888g of calcium hydroxide, Ca(OH)₂

no. of molecules = 7.22 x 10²⁴ (3s.f)

working no. of mole= 888/40+16(2)+1(2)

                            = 888/74

                             = 12 mol

no. of molecules= 12 x 6.02 x 10²³

                               ^{= 7.22 x 1024 (3s.f)}

Molar Gas volume

100

Calculate the volume of 5 mol of ethanol at r.t.p

volume= no. of mole x molar volume

          = 5 x 24

          = 120 dm³ 

200

Calculate the number of moles in 72dm³ of nitrogen gas, N₂ at r.t.p

no. mol = volume/molar volume 

            = 72/24

            = 3 mol

300

Calculate the volume of 16g of oxygen,O₂ at r.t.p

no. of mol = 16/2(16)

                =1/2

volume= no. of mole x molar volume

          = 1/2 x 24

          = 12 dm³ 

400

Calculate the mass in 120dm³ of oxygen, O₂ at r.t.p

mass= no. of mol x Mr

no. of mol= 120/24

              = 5 mol

mass= 5 x 2(16)

       = 160g 

500

How many mols of O₂ are there in 20 000cm³

volume in dm³ = 20 000cm³ / 1000

                      = 20dm³

mol= volume/ molar volume

     = 20/24

      = 0.833 (3s.f) mol