Exp. 2 : Open book quiz-

A reaction requires 2.5 moles of zinc oxide. How many grams would this equate to?

• 81.4 g

• 163.5 g

• 203.5 g

• 32.6 g

A teacher has given a lab student a white chemical sample and asks her to confirm that it contains 7.03 × 1023 formula units of sodium hydroxide (NaOH). Using the balance in the laboratory, what is the molar mass of NaOH.

• 0.03 g

• 7.03 g

• 40.0 g

What is the molar volume of a gas at STP?

• 1.0 atm/mol

• 22.4 L/mol

• 1.0 L/22.4 mol

• 22.4 atm/mol

How many moles of helium would you find in a birthday balloon that had a volume of 6.2 L? Assume conditions are at STP.

• 12 moles

• 22.4 moles

• 3.6 moles

• 0.28 moles

What is the density of carbon monoxide gas at STP conditions?

• 1.3 g/L

• 0.75 g/L

• 28 g/L

• 22.4 g/L