Ch. 7 pH and Ocean Acidification Exam

Carbon dioxide and seawater combine to form _____.

• calcium carbonate

• carbon monoxide

• carbonic acid 

• bicarbonate

Tags

NGSS.HS-ESS2-6

NGSS.HS-PS1-2

Marine organisms make their shells from calcium and ______.

• chloride

• carbonate

• hydrogen ion

• carbonic acid

What do some marine creatures do with the carbonate ion?

• use it as a food source

• use it as a defense mechanism

• use it to build shells and exoskeletons

• use it to cool body temperatures

Phenolphthalein turns from clear to pink when the pH of a solution becomes more _____.

• acidic

• basic

• neutral

• ionic

One drawback of litmus paper is that it ...

• Only tells you if a substance is an acid or a base

• is very expensive

• is messy

• has to be connected to a computer

Which of the following best describes the color change observed when a red litmus paper is in contact with an acidic solution?

• red

• blue

• purple

• not enough information

Tags

NGSS.MS-PS1-2

A student is using various pH indicators, including phenol red and bromothymol blue, to identify the pH of an unknown solution. After adding phenol red, the solution turns light yellow, and upon adding bromothymol blue, it turns green. What is the most likely pH range of the unknown solution?

• 3-4

• 6-7

• 9-10

• 12-13

Tags

NGSS.MS-PS1-2

A student wants to identify the pH of an unknown solution and decides to use both litmus paper and bromothymol blue as the pH indicator. After testing, the litmus paper turns red, and the bromothymol blue indicator turns green. Describe its acidity:

• strong acid

• weak acid

• weak base

• strong base

Tags

NGSS.MS-PS1-2

When a liquid in contact with a cabbage pH indicator turns purple, but turns yellow after adding an unknown chemical, what does this color change indicate about the unknown chemical?

• The unknown chemical is acidic.

• The unknown chemical is basic.

• The unknown chemical is neutral.

• The unknown chemical is not reactive with the cabbage indicator.

Tags

NGSS.MS-PS1-2

Name one chemical pH indicator that is best in determining if a solution is close to neutral?

• phenol red

• methyl orange

• thymol blue

• not enough information