Avogadro's Constant and the Mole

Question 1

Test information

Answer 1

• Scientific notation= multiple choice
• Word Amount in an equation= moles
• Word problems may use unit 2 formula names
• Determine the entity of a compound

Question 2

Relating mass on the scale (grams) to the number of molecules: Products

Answer 2

• The # of molecules also tell us the # of moles
• 4 CO2 → 4 x avgrodros #

Question 3

Number of entities

Answer 3

• Always one variable you know
• Avogadro’s number
• N= number of entities (atoms, molecules, formula units)
• n= number of moles
• NA= advagdros number

Question 4

Comparison of both equations

Answer 4

• Common variable is # of moles
• Both equations can be connected through this one variable
• Both equations will be used together
• Always find # of moles first then work with other equation

Question 5

Determining number of entities in compounds

Answer 5

• If you know # of molecules, you can find # of atoms
• Multiply molecule by ratio
• In 2 H2O, you have 2 H and 4 O
• If a formula (HCN) has 3.33x1022 atoms, find the number of atoms in 1 molecules (3 atoms) and multiply by N by 1/3

Question 6

Conversions: Moles and grams

Answer 6

• moles –> grams= multiply atomic mass/molar mass
• grams–> moles= divide atomic mass/molar mess

Question 7

Conversions: moles and atoms/molcules

Answer 7

• moles –> atoms/molclues = x 6.02 x 10^23
• atoms/molecules –> moles = / 6.02 x 10^23