Answer
a) Not pure
b) Not pure
c) Pure or nearly pure
d) Pure or nearly pure
e) Pure or nearly pure
f) Not pure
g) Pure or nearly pure
h) Pure or nearly pure
Work Step by Step
a) Baking soda is a mixture of bicarbonate and a weak acid
b) Lemon juice contains water and a mixture of acids, such as citric acid
c) Propane gas is a pure or nearly pure substance, $C_{3}H_{8}$
d) Aluminum foil is made from a pure substance, Al
e) Ibuprofen is a pure substance
f) Bourbon whiskey is a mixture of several different compounds
g) Helium gas is a pure substance, He
h) As water travels up through and aquifer, many pollutants and bacteria are filtered out, so it is a nearly pure substance
