unit 4 review

How many moles of carbon atoms are there in 5g of carbon?

• 60 mol
• 17 mol
• 0.42 mol
• 7 mol

How many molecules are there in 5.9 moles of NaCl?

• 3.5x10²⁴molecules
• 9.79x10^-24molecules
• 1.02x10²³molecules

In chemistry, a "mole" is:

• The mass of an atom
• a large number used to count particles
• based on the volume of a substance

The number 6.02 x 10²³ is called...

• Obama's number
• Bohr's number
• Trump's number
• Avogadro's number

We use the periodic table to calculate...

• mass
• molar mass
• moles

What is the molar mass of NaCl?

• 58.45g/mol
• 28g/mol
• 12g/mol
• 6.02 x 10²³

How do we get mass from moles?

• multiply by avogadro's number
• multiply by molar mass
• divide by avogadro's number
• divide by molar mass

Which has more molecules?

• 1 mole H₂O
• 1 mole Al(OH)₃
• 1 mole NaCl
• There are all the same

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

What is the percent by mass of magnesium in MgO?

• 20%
• 40%
• 50%
• 60%