Phys/Chem Changes - pH Scale

Which pair of listed properties correctly describes most acids?

• They contain hydrogen ions (H⁺) and have a bitter taste.

• They contain hydrogen ions (H⁺) and have a sour taste.

• They contain hydroxide ions (OH-) and have a bitter taste.

• They contain hydroxide ions (OH-) and have a sour taste.

Students were asked to test several unknown substances to determine if the substances are acids or bases. During the first test, a drop of phenolphthalein turned the unknown solution bright pink. What can be inferred about the substance?

• It is neutral.

• It tastes sour.

• It has a pH ranging from 1-6.

• It has a pH ranging from 8-14.

Which statement accurately describes water?

• It is a basic solution.

• It is a neutral solution.

• It will turn bright pink when phenolphthalein is added.

• It will turn red litmus paper a blue color upon contact.

Which color would red litmus paper be after it is place in an acid?

• Blue

• Purple

• Red

• Yellow

Some common substances and their pH values are shown in the diagram. What color change would occur if blue litmus paper were dipped in lemon juice?

• It would stay blue.

• It would turn green.

• It would turn violet.

• It would turn red.

Tags

NGSS.MS-PS1-2

A reaction occurs in a beaker of fluid, and a white substance settles to the bottom. This precipitate is evidence that what process has occurred?

• Chemical Reaction

• Gas Exchange

• Heat Exchange

• Physical Change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What would be the breaking up of a large rock into small rocks be considered?

• Chemical Property

• Chemical Reaction

• Physical Change

• Physical Property

A student wants to demonstrate physical and chemical changes using a piece of paper. Which table accurately shows the procedures for both a physical and chemical change using the piece of paper?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

John measures the temperature of a substance after a chemical reaction. The diagram shows the thermometer at the end of the reaction. What is the temperature of the substance?

• 21

• 22

• 24

• 25

Tags

NGSS.MS-PS1-4

Which example represents an entirely physical change?

• Black iron turns to reddish-brown when it rusts.

• Water boils which creates bubbles and water vapor.

• Wood burns to produce ashes and gases.

• Carbon dioxide combines with limewater to produce chalk.