Question

Morgan observes changes that occur to substances during four experiments. She records her observations in a table.


Experiment Observation Type of Change
two 100 mL beakers of liquids are combined a precipitate is formed physical
an egg is placed in a frying pan over high heat the liquid egg becomes solid chemical
a candle is burned for 2 hours the solid wax melts into liquid physical
two 300 mL beakers with of clear liquid are combined the liquid turns blue chemical

Which mistake does Morgan make in her table?

a
A physical change occurs when an egg is cooked because there is a change in phase.
b
A chemical change occurs when two liquids combine and a precipitate is formed.
c
A chemical change occurs when a candle is burned because there is a change in phase.
d
A physical change occurs when the liquid turns blue because there was no precipitate formed.

Answer 1

b

The formation of a precipitate indicates a chemical change (new substance formed), so labeling the combination that produced a precipitate as a physical change is incorrect.