Acids and Bases (QUIZ 3)

Question 1

Universal indicator was added to a clear liquid. The liquid turned green. Which conclusion does the indicator evidence support?

A) The liquid is an acid.
B) The liquid has a pH greater than 7.
C) The liquid is pure water
D) The liquid has a neutral pH.

Answer 1

D) The liquid has a neutral pH.

There are substances other than water that have a neutral pH.

Question 2

Which statement correctly describes the relationship between a substance A that has a pH of 8 and a substance B that has a pH of 10?

A) Substance A is a stronger base than Substance B because it has a higher pH.
B) Substance B is more alkaline than Substance A because it has a higher pH.
C) Substance A is more alkaline than Substance A because it has a lower pH.
D) Substance B is a stronger base than Substance A because it has a higher pH.

Answer 2

B) Substance B is more alkaline than Substance A because it has a higher pH.

Nothing is known about the tendency of either substance to break up in solution. The only conclusion that can be made from the information is one of relative alkalinity.

Question 3

When a few drops of lemon juice are added to black tea, there is a distinct color change. Select the best inference statement that explains why.

A) Black tea contains chemicals that act as pH indicators.
B) Lemon juice is a lighter color liquid that dilutes the black tea color.
C) Black tea is a base and lemon juice is an acid.
D) Lemon juice is a strong acid and black tea is a weak acid.

Answer 3

A) Black tea contains chemicals that act as pH indicators.

None of the other answers is supported by the observation.