Grade 7 Acids and Bases

Which of the following word pairs correctly completes the sentence below?
_______ are corrosive substances characterized as having a strong smell, a sour taste, and a _______.

• Acids; pH less than 7
• Acids; pH greater than 7
• Bases; pH greater than 7
• Bases; pH less than 7

Tags

CCSS.RI.9-10.4

CCSS.RI.9-10.4

CCSS.RI.8.4

CCSS.RI.11-12.4

CCSS.RI.7.4

The esophagus is the tube that connects the mouth to the stomach. Heartburn occurs when some of the stomach juices flow backwards up the esophagus. To help relieve heartburn, a person should take medicine that is

• neutral
• basic
• 
  acidic or basic.
  
• acidic

If an acid is combined with a base of equal strength, the result will most likely be

• a neutral solution.
• a stronger acid.
• impossible to tell without testing the pH.
• a stronger base

Holly has an unknown substance in a beaker. She wants to determine the relative pH of the unknown substance. She places a piece of blue litmus paper into the substance, and the litmus paper stays blue.
The substance in the beaker

• is a base.
• has a neutral pH.
  
• is an acid.
• does not have a pH.

Which of the following is a base?

• orange juice
• water
• vinegar
• dishwashing detergent

Litmus paper can be used to determine the _______ of a substance.

• relative volume
• temperature
• relative pH
• chemical formula

Litmus paper can be used to determine the _______ of a substance.

• relative volume
• temperature
• relative pH
• chemical formula

Which of the following statements is correct?

• Blue litmus paper turns red when placed in a base.
• Red litmus paper turns blue when placed in a base.
• Blue litmus paper stays blue when placed in an acid.
• Red litmus paper stays red when placed in a base.

Carrie's teacher hands out test tubes filled with different chemicals and tells the students to identify their liquid as an acid, base, or neutral chemical. Carrie's test tube contains a clear chemical. She adds phenolpthalein to her test tube and gently moves the tube from side to side. A few moments later, the chemical in the test tube turns bright pink.
What type of chemical does Carrie have?

• Carrie has a neutral chemical.
• Carrie has an acidic chemical.
• Carrie has a basic chemical.
• The type of chemical Carrie has cannot be determined.

 Which of the following is an acid?

• shampoo
• baking soda
• orange juice
• water