Unit 1-AP short quiz

According to the information in the table above, a 1.00 g sample of which of the following contains the greatest mass of oxygen?

• Na₂O

• MgO

• K₂O

• CaO

A student has a 1g

sample of each of the following compounds: NaCl

, KBr

, and KCl

. Which of the following lists the samples in order of increasing number of moles in the sample?

• NaCl<KCl<KBr

• NaCl<KBr<KCl

• KCl<NaCl<KBr

• KBr<KCl<NaCl

A solution of methanol, CH₃OH, in water is prepared by mixing together 128 g of methanol and 108 g of water. The mole fraction of methanol in the solution is closest to

• 0.8

• 0.6

• 0.4

• 0.7

Which of the following numerical expressions gives the number of particles in 2.0g

of Ne

?

• A

• B

• C

• D

How many carbon atoms are contained in 2.8 g of C₂H₄ ?

• 1.2 x 10²³

• 3.0 x 10²³

• 3.0 x 10²³

• 1.2 x 10²⁴

A 23.0g sample of a compound contains 12.0g of C, 3.0g of H, and 8.0g of O. Which of the following is the empirical formula of the compound?

• CH₃O

• C₂H₆O

• C₃H₉O₂

• C₄H₁₂O₂