TH/CH - Moles Calculations

Which is the correct formula for calculating moles?

• mass X RFM

• Mass / RFM

• RFM / Mass

How many moles are in 0.44g of Carbon Dioxide (RFM = 44)

• 0.1

• 0.01

• 0.001

• 0.0001

How many moles are in 3.5g of Sodium Chloride to 2 d.p? (RFM= 58.5)

• 0.06

• 0.05

• 16.7

• 16.8

How is RFM calculated?

• Multiply the masses of the individual atoms together

• Add the masses of the individual atoms together

What is the RFM of Magnesium Chloride (MgCl₂)?

(Mg = 24, Cl = 35.5)

• 95

• 59.5

• 95

• 71

Calculate the RFM of Carbon Dioxide (CO₂)

(C =12, O = 16)

• 38

• 44

• 4

• 28

Calculate the RFM of Magnesium Hydroxide (Mg(OH)₂)

(Mg = 24, O = 16, H = 1)

• 42

• 41

• 56

• 58

If 0.5moles of H2SO4 is reacted with 0.5moles of NaOH which reagent is in excess. H2SO4 + 2NaOH --> Na2SO4 + 2H2O

• NaOH

• H2SO4

• Na2SO4

• H2O

What is the equation for calculating mass using the moles triangle?

• Mass x RFM

• Moles x RFM

• Moles / RFM

• Mass / RFM