NGS CH 11 Section 02: Acids, Bases, and Salts Quiz

What is an acid?

• A substance that produces hydroxide ions (OH-) in a solution

• A substance that produces hydrogen ions (H+) in a solution

• A substance that feels slippery

• A substance that tastes bitter

Answer explanation

An acid is defined as a substance that produces hydrogen ions (H+) in a solution. This is the key characteristic that distinguishes acids from bases, which produce hydroxide ions (OH-).

Tags

NGSS.MS-PS1-1

Which of the following is a characteristic of acids?

• They feel slippery

• They taste sour

• They taste bitter

• They are crystalline solids

Answer explanation

A characteristic of acids is that they taste sour. This is a well-known property, while the other options describe bases or do not apply to acids.

What is a base?

• A substance that produces hydrogen ions (H+) in a solution

• A substance that produces hydroxide ions (OH-) in a solution

• A substance that tastes sour

• A substance that is an electrolyte

Answer explanation

A base is defined as a substance that produces hydroxide ions (OH-) in a solution. This distinguishes it from acids, which produce hydrogen ions (H+). Therefore, the correct answer is the one that describes hydroxide ion production.

Which of the following is a characteristic of bases?

• They feel slippery

• They are electrolytes

• They taste sour

• They react with metals

Answer explanation

Bases are known for their slippery feel, which is a result of their ability to react with oils and fats. This characteristic distinguishes them from acids, which typically taste sour.

What happens when an acidic and basic solution are combined?

• They form a stronger acid

• They form a stronger base

• Neutralization occurs, forming water and salt

• They produce hydrogen gas

Answer explanation

When an acidic solution reacts with a basic solution, they undergo neutralization, resulting in the formation of water and salt. This is the correct process, as opposed to forming stronger acids or bases or producing hydrogen gas.

What is neutralization?

• A reaction between two acids

• A reaction between two bases

• A chemical reaction between an acid and a base in a water solution

• A process of dissolving a solid in a liquid

Answer explanation

Neutralization is specifically a chemical reaction between an acid and a base in a water solution, resulting in the formation of water and a salt. This distinguishes it from reactions involving only acids or bases.

What is a salt?

• A substance that produces hydrogen ions (H+) in a solution

• A compound that tastes sour

• A compound formed when negative ions of an acid combine with positive ions from a base

• A substance that produces hydroxide ions (OH-) in a solution

Answer explanation

A salt is formed when the negative ions of an acid combine with the positive ions from a base, resulting in a neutral compound. This definition distinguishes salts from acids and bases, which produce H+ and OH- ions, respectively.

What is an indicator?

• A compound that changes colors to help determine whether something is an acid or a base

• A substance that produces hydrogen ions (H+)

• A compound that tastes bitter

• A substance that feels slippery

Answer explanation

An indicator is a compound that changes colors in response to pH levels, helping to identify whether a solution is acidic or basic. This makes the first choice the correct answer.

What color does litmus turn when something is acidic?

• Blue

• Yellow

• Green

• Red

Answer explanation

Litmus paper turns red in the presence of an acidic solution. This color change indicates that the pH level is below 7, confirming the substance is acidic.

Which of the following is NOT a characteristic of bases?

• They feel slippery

• They taste sour

• They taste bitter

• They are crystalline solids in an undissolved state

Answer explanation

Bases do not taste sour; that characteristic is typical of acids. Bases are known for their slippery feel, bitter taste, and can exist as crystalline solids when undissolved.