REVIEW: Moles<-->Mass

The molar mass of an element is equal to its...

• Atomic mass (from the periodic table)

• Atomic number (from the periodic table)

• Oxidation number

• Valence electrons

A chemist needs to prepare a solution and requires the exact molar mass of Ba(OH)₂ for the calculation. What is the molar mass of Ba(OH)₂?

• 153.49 g/mol

• 171.35 g/mol

• 56.24 g/mol

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TEKS 8 (A) (B) 2021

A chef is preparing a special sauce and realizes they have exactly 50.0 grams of water (H₂O) left. How many moles of H₂O does this amount to?

• 2.77 moles

• 18.02 moles

• 901 moles

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TEKS

8

(A)

(B)

2021

A chemist needs to prepare a solution and requires exactly 0.750 moles of calcium chlorate, Ca(ClO₃)₂. How much mass of calcium chlorate should the chemist weigh out?

• 155.24 grams

• 206.98 grams

• 128.65 grams

A chemist adds 2.50 moles of sodium sulfate, Na₂SO₄, to a solution for an experiment. What mass of the substance was added?

• 297.65 grams

• 142.05 grams

• 355.13 grams

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TEKS

8

(A)

(B)

2021

A chemist is working on a project that involves the use of aluminum carbonate, Al₂(CO₃)₃. What is the molar mass of aluminum carbonate used in the project?

• 54.99 g/mol

• 233.99 g/mol

• 185.99 g/mol

If a chemist has 3.0 moles of sodium hydroxide, NaOH, in their laboratory, what is the mass of this compound?

• about 40 grams

• about 23 grams

• about 120 grams

How many moles are present in 32.3 grams of carbon dioxide (CO₂)?

• 44.01 moles
• 1421.52 moles
• 32.3 moles
• 0.73 moles

What is the mass of 2.50 mol of oxygen gas O₂?

• 40 g
• 80 g
• 16 g
• 32 g

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