Lesson Worksheet: Moles Chemistry

In this worksheet, we will practice defining the mole in terms of Avogadro’s constant and converting the mass of a substance to an amount of moles.

Q1:

What is the mass of 0.443 mol of hydrazine (NH)24? Give your answer to 1 decimal place.

Q2:

Sulfuric acid has a relative formula mass of 98 g/mol. What is the mass of 2.5 mol of sulfuric acid?

Q3:

Ammonia has a relative formula mass of 17. How many moles of ammonia molecules are there in 34 g of ammonia?

Q4:

A 24 g sample of lithium hydride contains 3.0 moles of LiH units. What is the relative formula mass of lithium hydride?

Q5:

How many moles of atoms are there in 12 g of carbon-12?

Q6:

How is the atomic mass unit (u) defined?

  • A1 u is equal to the mass of a neutron.
  • B1 u is equal to 112th of the mass of a carbon-12 atom.
  • C1 u is equal to the mass of a proton.
  • D1 u is equal to the mass of a carbon-12 atom.
  • E1 u is equal to the mass of a hydrogen-1 atom.

Q7:

A prospector panning for gold in a river collects 15.81 g of pure gold. Calculate, to 2 decimal places, the number of Au atoms in this quantity of gold. [Au = 197 g/mol]

  • A4.41×10 atoms
  • B7.50×10 atoms
  • C6.70×10 atoms
  • D3.63×10 atoms
  • E4.83×10 atoms

Q8:

To 2 decimal places, how many atomic mass units (u) are there in one gram (g) of a substance?

  • A6.02×10
  • B7.24×10
  • C6.24×10
  • D6.63×10
  • E1.51×10

Q9:

Diamond is one form of elemental carbon. An engagement ring contains a diamond weighing 1.5 carats (1 carat = 200 mg). How many atoms are present in the diamond? Give your answer to 1 decimal place.

  • A1.5×10 atoms
  • B7.5×10 atoms
  • C1.0×10 atoms
  • D1.5×10 atoms
  • E2.6×10 atoms

Q10:

The approximate daily dietary requirement of the amino acid leucine, CHNO6132, is 15 mg/kg of body weight. For a 65 kg person, what is this requirement in millimoles?

This lesson includes 18 additional questions and 56 additional question variations for subscribers.

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