Acid-Base Definitions

What is the taste associated with acids?

• Sweet

• Bitter

• Sour

• Salty

Answer explanation

The taste associated with acids is sour. This is a fundamental characteristic of acidic substances, which often impart a tangy flavor, distinguishing them from sweet, bitter, or salty tastes.

Which of the following is a property of bases?

• They are non-electrolytes.

• They react with metals to produce hydrogen gas.

• They turn litmus paper blue.

• They have a sour taste.

Answer explanation

Bases are known to turn litmus paper blue, which is a key property distinguishing them from acids. The other options do not accurately describe the properties of bases.

According to the Arrhenius theory, what does an acid produce in aqueous solution?

• Hydrogen ions

• Sodium ions

• Chloride ions

• Hydroxide ions

Answer explanation

According to the Arrhenius theory, an acid is defined as a substance that increases the concentration of hydrogen ions (H+) in aqueous solution, making 'Hydrogen ions' the correct answer.

Which of the following is a Brønsted-Lowry base?

• A molecule that donates a hydroxide ion

• A molecule that accepts a hydroxide ion

• A molecule that donates a hydrogen ion

• A molecule that accepts a hydrogen ion

Answer explanation

A Brønsted-Lowry base is defined as a substance that accepts a hydrogen ion (H+). Therefore, the correct choice is 'A molecule that accepts a hydrogen ion', as it aligns with this definition.

What is the ion formed when hydrogen chloride is dissolved in water?

• Hydronium ion

• Hydroxide ion

• Sodium ion

• Chloride ion

Answer explanation

When hydrogen chloride (HCl) dissolves in water, it ionizes to form hydronium ions (H3O+) and chloride ions (Cl-). The hydronium ion is the primary species responsible for the acidic properties of the solution.

Which of the following is a common property of acids?

• They are slippery to the touch.

• They have a bitter taste.

• They change litmus paper to red.

• They do not react with metals.

Answer explanation

A common property of acids is that they change litmus paper to red, indicating their acidic nature. The other options describe properties of bases or are incorrect.

What is the definition of a Lewis acid?

• A substance that accepts an electron pair

• A substance that donates an electron pair

• A substance that accepts a proton

• A substance that donates a proton

Answer explanation

A Lewis acid is defined as a substance that accepts an electron pair. This distinguishes it from other definitions, such as Bronsted acids, which are proton donors. Therefore, the correct choice is that it accepts an electron pair.

Which of the following is a monoprotic acid?

• Sulfuric acid

• Phosphoric acid

• Hydrochloric acid

• Acetic acid

Answer explanation

Hydrochloric acid is a monoprotic acid because it can donate only one proton (H+) per molecule in an aqueous solution. In contrast, sulfuric acid and phosphoric acid can donate more than one proton, making them polyprotic.

What is the result of a reaction between an acid and a base?

• Hydroxide ions and a salt

• Hydrogen gas and a salt

• Water and a salt

• Hydronium ions and a salt

Answer explanation

The reaction between an acid and a base typically produces water and a salt. This neutralization process involves the combination of hydrogen ions from the acid and hydroxide ions from the base, resulting in water.

Which of the following is a property of strong acids?

• They ionize completely in water.

• They have a bitter taste.

• They do not change the color of indicators.

• They are weak electrolytes.

Answer explanation

Strong acids ionize completely in water, meaning they dissociate fully into ions, which is a key characteristic. The other options do not accurately describe strong acids.