3.2 Use of amount of substance in relation to masses of pure substances

• What is a mole (mol) used to measure?

  Amount of a substance
• What is the value of Avogadro's number?

  6.022 × 10²³
• Match the unit with its description:

  Mole ↔️ 6.022 × 10²³ particles

  Gram ↔️ Mass of 1 molecule in carbon-12 standard

  Litre ↔️ Volume occupied by gases at standard conditions
• How is molar mass calculated?

  Sum of atomic masses
• A mole is defined as the quantity of a substance that contains as many elementary entities as there are atoms in 12 grams of carbon-12
• 1 mole of water contains 6.022 × 10²³ water molecules.


  True
• Molar mass is measured in grams per mole
• The molar mass of water (H₂O) is approximately 18.02 g/mol.


  True
• What is the relationship between the mole and Avogadro's number?

  1 mole = 6.022 × 10²³ entities
• Match the unit with its description:

  Mole ↔️ 6.022 × 10²³ particles

  Molar Mass ↔️ Mass of 1 mole of a substance
• How is the molar mass of a substance calculated?

  Sum of atomic masses
• What is the atomic mass of hydrogen (H)?

  1.008 g/mol
• What data is needed to calculate molar mass using the periodic table?

  Atomic masses
• What is the atomic mass of carbon (C)?

  12.01 g/mol
• To convert mass to moles, divide the given mass by the molar mass.
• What is the value of Avogadro's number?

  6.022 × 10²³
• What is the numerical value of Avogadro's number?

  6.022 × 10²³
• The mole is defined as the quantity containing 6.022 × 10²³ entities.
• Match the unit with its symbol and amount:

  Mole ↔️ mol, 6.022 × 10²³ particles

  Gram ↔️ g, Mass of 1 molecule in carbon-12 standard

  Litre ↔️ L, Volume occupied by gases at standard conditions
• Molar mass is measured in grams per mole.
• The molar mass of H₂O is approximately 18.02 g/mol.


  True
• Molar mass is the mass of 1 mole of a substance.
• Multiply each element's atomic mass by the number of its atoms in the substance.
• The molar mass of glucose is calculated by summing the atomic masses of 6 carbon, 12 hydrogen, and 6 oxygen atoms.


  True
• What is the first step in converting mass to moles?

  Identify molar mass
• 36 grams of water contains 2 moles of water molecules.


  True
• To find the number of moles, divide the given mass of the substance by its molar mass
• How many moles are in 36 grams of water?

  2 moles
• To convert moles to mass, multiply the number of moles by the molar mass.


  True
• The number 6.022 × 10²³ is known as Avogadro's number
• What is the relationship between moles, molar mass, and the number of particles in stoichiometry?

  Interrelated
• Steps to calculate the number of particles from a given mass using Avogadro's number:

  1️⃣ Identify the molar mass of the substance

  2️⃣ Calculate the number of moles using Moles = Mass / Molar Mass

  3️⃣ Use Avogadro's number to find the number of particles
• The molar mass of a substance is the mass of 1 mole
• The molar mass of H₂O is calculated as (2 × 1.008 g/mol) + (1 × 16.00 g/mol).


  True
• The molar mass of a substance is measured in grams per mole.
• One mole of H₂O contains 2 hydrogen atoms and 1 oxygen atom.

  True
• The molar mass of H₂O is 18.02 g/mol.
• Steps to calculate molar mass using periodic table data

  1️⃣ Identify elements and their atomic masses

  2️⃣ Multiply atomic mass by number of atoms

  3️⃣ Add up all individual masses
• What is the total molar mass of glucose (C₆H₁₂O₆)?

  180.16 g/mol
• 36 grams of H₂O is equal to 2 moles.


  True