Acids Bases and Salts

What is the pH range of an acid?

• 0-14

• less than 7

• exactly 7

• greater than 7

Answer explanation

An acid is defined as a substance that has a pH less than 7. The pH scale ranges from 0 to 14, where values below 7 indicate acidity, exactly 7 is neutral, and above 7 indicates alkalinity.

What is the pH range of a base?

• 0-14

• less than 7

• exactly 7

• greater than 7

Answer explanation

A base has a pH greater than 7, indicating it is alkaline. The pH scale ranges from 0 to 14, with values below 7 being acidic, exactly 7 being neutral, and above 7 being basic.

What is the pH range of a neutral solution?

• 0-14

• less than 7

• exactly 7

• greater than 7

Answer explanation

A neutral solution has a pH of exactly 7. Values below 7 indicate acidity, while values above 7 indicate alkalinity. Therefore, the correct answer is 'exactly 7'.

What happens when an acid and a base react? (choose all that apply)

• They neutralize each other

• water is formed as a product

• salt is formed as a product

• The acid corrodes the base

Answer explanation

When an acid and a base react, they neutralize each other, producing water and salt as products. The statement about corrosion is incorrect, as acids do not corrode bases in this reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How do acids taste?

• Sweet

• Sour

• Salty

• Bitter

Answer explanation

Acids typically taste sour, which is a characteristic flavor associated with substances like vinegar and citrus fruits. This distinguishes them from sweet, salty, or bitter tastes.

Tags

NGSS.MS-LS1-8

How do bases taste?

• Sweet

• Sour

• Salty

• Bitter

Answer explanation

Bases typically taste bitter, which is a characteristic that distinguishes them from acids, which taste sour. This is why the correct answer is 'Bitter'.

Tags

NGSS.MS-LS1-8

What type of acid is in your stomach?

• Battery

• Hydrochloric

• Neutral

• Antacid

Answer explanation

The acid in your stomach is hydrochloric acid, which helps digest food and kill harmful bacteria. Battery acid is sulfuric acid, neutral refers to a pH of 7, and antacids are substances that neutralize stomach acid.

Tags

NGSS.MS-PS1-2

Which substance increases the number of hydroxide ions (OH-) in a solution?

• Acid

• Base

• Neutral

• Citrus

Answer explanation

A base increases the number of hydroxide ions (OH-) in a solution, making it more alkaline. In contrast, acids increase hydrogen ions (H+), while neutral substances do not significantly change ion concentrations.

Which substance increases the number of hydrogen ions (H+) in a solution?

• Acid

• Base

• Neutral

• Bleach

Answer explanation

An acid increases the number of hydrogen ions (H+) in a solution, which is why it is the correct choice. Bases, on the other hand, decrease H+ concentration, while neutral substances do not affect it.

What will an indicator tell you? (Check all that apply)

• Whether a substance is an acid or a base

• Where on the pH scale the substance will fall

• What color the substance is

• What elements are in the substance

Answer explanation

An indicator shows whether a substance is an acid or a base and indicates its position on the pH scale. It does not provide information about the color of the substance or its elemental composition.