Question 1: A compound was discovered whose composition by mass is 85.6% C and 14.4% H. Which of the following could be the molecular formula of this compound?
a. CH₄
b. C₂H₄
c. C₃H₄
d. C₂H₆
e. C₃H₈

Question 2: What is the molor mass of acetaminophen, C₈H₉NO₂ ?
a. 151 g/mol
b. 76 g/mol
c. 43 g/mol
d. 162 g/mol
e. 125 g/mol

Question 3: A magnesium ion, Mg²⁺ has how may electrons?

Question 4: How many carbon atoms are there in 10 lbs of sugar, C₁₂H₂₂O₁₁?
a. 9.6 x 10²⁵ atoms
b. 8.0 x 10²⁴ atoms
c. 159 atoms
d. 4.21 atoms
e. 342 atoms

Question 5: How many O atoms are there in 51.4 g CaSO₄?
a. 4
b. 2.40 x 10²⁴
c. 1.13
d. 9.09 x 10²³
e. 2.28 x 10²³

Question 6: The element oxygen consists of three naturally occurring isotopes: Oxygen-16, Oxygen-17, Oxygen-18. The atomic mass of oxygen is 16.0 amu. What can be implied about the relative abundances of these isotopes?
a. More than 50% of all O atoms are O-17.
b. Almost all O atoms are O-18.
c. Almost all O atoms are O-17.
d. The isotopes all have the same abundance, i.e. 33.3%.
e. The abundances of O-17 and O-18 are very small.

Question 7: Rutherford's experiment with alpha particle scattering by gold foil established that:
a. protons are not evenly distributed throughout an atom.
b. electrons have a negative charge.
c. electrons have a positive charge.
d. atoms are made of protons, neutrons, and electrons.
e. protons are 1840 times heavier than electrons.

Question 8: What is the mass of one copper atom?
a. 1.055 x 10^-22 g
b. 63.55 g
c. 1 amu
d. 1.66 x 10^-24 g
e. 9.476 x 10²¹ g

Question 9: An anion is defined as
a. A charged atom or group of atoms with a net negative charge.
b. A stable atom
c. A group of stable atoms
d. An atom or group of atoms with a net positive charge

Question 10
An oxide ion O^2- has how many electrons?