ACIDS AND BASES

Multiple Choice

In an aqueous solution, an acid

• absorbs hydrogen ions (H⁺)

• donates hydrogen ions (H⁺)

• releases oxygen gas (O₂)

• increases the pH of the solution

Multiple Choice

According to Arrhenius, acids are

• Substances that release hydroxide ions (OH-)
• Substances that do not react with water
• Substances that produce oxygen gas when dissolved in water
• Substances that dissociate in water to produce hydrogen ions (H+)

Multiple Select

Which of the following people contributed to the definition and classification of acids?

choose all that apply.

• Svante Arrhenius

• Charles Darwin

• Johannes Nicolaus Bronsted

• Thomas Martin Lowry

Multiple Choice

According to Arrhenius, H₂SO₄ is an acid because

• H₂SO₄ dissociates in water to produce H⁺ ions

• H₂SO₄ is a base

• H₂SO₄ produces OH^- ions in water

• H₂SO₄ does not react with water

Multiple Choice

According to Arrhenius' definition, a base is a

• substance that dissociates in water to release hydroxide (OH^-) ions

• substance that forms salts with acids
• substance that does not react with water
• substance that releases hydrogen (H⁺) ions in water

Multiple Select

One limitation of Arrhenius' definition of acids is that,.................................

choose all that apply

• It only applies to substances that dissociate in water.
• It does not consider the strength of acids.
• It is too simplistic for modern chemistry.
• It excludes non-aqueous solutions.

Multiple Choice

NaOH is a base because,

• NaOH is a base because it dissociates in water to produce hydroxide ions.
• NaOH is a base because it is highly flammable.
• NaOH is a base because it is a gas at room temperature.
• NaOH is a base because it produces acidic ions.

Multiple Choice

According to Bronsted-Lowry, an acid is a

• Proton acceptor
• Proton donor
• Electron donor

• Electron acceptor

Multiple Choice

Difference between Arrhenius and Bronsted-Lowry acid is that,

• Arrhenius acid dissociates in water to produce H⁺ ions, while Bronsted-Lowry acid donates a proton (H⁺ ion) to another substance.

• Arrhenius acid is a weak acid, while Bronsted-Lowry acid is a strong acid
• Arrhenius acid produces OH^- ions, while Bronsted-Lowry acid produces H⁺ ions

• Arrhenius acid donates a proton, while Bronsted-Lowry acid dissociates in water

Multiple Choice

Bronsted-Lowry defined bases as

• proton donors
• acidic substances
• proton acceptors
• electron acceptors

Multiple Choice

Ammonia is an example of

• Arrhenius acid

• Arrhenius base

• Bronsted-Lowry acid

• Bronsted-Lowry base

Multiple Choice

According to Bronsted-Lowry, ammonia is a base because

• Ammonia can accept a proton (H⁺)

• Ammonia cannot form a conjugate acid
• Ammonia is a neutral molecule
• Ammonia can donate a proton (H⁺)

Multiple Choice

What is an acid-base conjugate pair?

• An acid-base conjugate pair consists of an acid that accepts a proton and a base that donates a proton.
• An acid-base conjugate pair consists of a base that donates a proton and an acid that accepts a proton.
• An acid-base conjugate pair consists of two acids that donate protons.
• An acid-base conjugate pair consists of an acid that donates a proton and a base that accepts a proton.

Multiple Choice

How do acid-base conjugate pair differ?

• Acid-base conjugate pairs differ by the presence or absence of a proton.
• Acid-base conjugate pairs differ by their color
• Acid-base conjugate pairs differ by their molecular weight
• Acid-base conjugate pairs differ by their boiling point

Multiple Choice

What is the Lewis concept of acids?

• An acid is a substance that can accept a pair of electrons.
• An acid is a substance that can form a covalent bond.
• An acid is a substance that can donate a proton.
• An acid is a substance that can donate a pair of electrons.

Multiple Choice

According to Lewis, a base is

• substance that can donate a proton or accept an electron pair in reactions
• substance that can donate an electron pair in reactions

• substance that can neither accept a proton nor donate an electron pair in reactions
• substance that can only accept a proton in reactions

Multiple Choice

How does Lewis concept prove that ammonia is a base?

• Ammonia is considered a base because it can donate electron pair according to Lewis concept.

• Ammonia is considered a base because it can donate a proton according to Lewis concept.
• Ammonia is considered a base because it is a strong acid according to Lewis concept.
• Ammonia is considered a base because it is a neutral compound according to Lewis concept.

Multiple Select

Which of the following is an example of a household acid?

• Vinegar
• Coffee
• Bleach
• Lemonade

Multiple Choice

The acid found in vinegar is

• sulfuric acid
• acetic acid
• hydrochloric acid
• citric acid

Multiple Choice

When you bitten by an insect, you feel the pain becuase

• The pain is caused by the proteins in the insect's saliva contains formic acid.

• The pain is caused by the insect's wings flapping
• The pain is caused by the insect's bright colors
• The pain is caused by the insect's size

Multiple Choice

Vitamin C is also known as

• lactic acid
• folic acid
• ascorbic acid
• citric acid

Multiple Choice

Lime tastes sour, because it is

• neutral

• basic

• acidic
• salty

Multiple Choice

A solution of pH of 9 is

• Acidic
• Alkaline
• Neutral
• Basic

Multiple Choice

What is acids effect on a red litmus paper?

• Turns the red litmus paper yellow
• Turns the red litmus paper green
• Turns the red litmus paper blue
• Has no observable effect

Multiple Choice

Acids conduct electricity because

• Acids ionize in water, producing positively charged hydrogen ions (H⁺).

• Acids are solid at room temperature
• Acids are non-reactive substances
• Acids are poor conductors of heat

Multiple Choice

What is acids effect on a blue litmus paper?

• Turns red
• Changes to yellow
• Remains blue
• Turns green

Multiple Choice

Bases taste

• Sweet
• Bitter
• Sour
• Salty

Multiple Choice

What is neutralization reaction?

• Neutralization reaction involves the formation of only water
• Neutralization reaction occurs between two acids
• Neutralization reaction results in the formation of a gas
• A neutralization reaction is a chemical reaction between an acid and a base, resulting in the formation of water and a salt.

Multiple Choice

When bases reacts with acids, what products are produced?

• Gas and solid
• Acid and base
• Salt and sugar
• Salt and water

Multiple Choice

A reaction between a reactive metal and a base produces

• oxygen gas and a salt
• carbon dioxide and a salt
• water and a salt
• hydrogen gas and a salt

Multiple Choice

When acids mix with water,

• They combine to form a gas
• They solidify
• They dissociate into ions
• They evaporate

Multiple Choice

Acids reacts with carbonates to produce

• salt, water, and carbon dioxide gas
• carbon dioxide gas, salt, and hydrogen gas
• water, salt, and nitrogen gas
• sugar, salt, and oxygen gas

Multiple Choice

What is produced when acids react with sulphite or bisulphite,

• Sulphuric oxide
• Hydrogen gas
• Sulphuric acid
• Sulphur dioxide gas

Multiple Choice

Acids react with metallic sulphides to form

• metal salts and hydrogen sulfide gas
• metal carbonates and sulfuric acid
• metal hydroxides and sulfur dioxide gas
• metal oxides and hydrogen gas

Multiple Choice

Bases react with the metals to produce

• metal hydroxides and oxygen gas
• metal oxides and water
• metal salts and hydrogen gas
• metal carbonates and carbon dioxide

Multiple Choice

When a base reacts with a reactive metals, what products are produced?

• Salt and hydrogen gas
• Nitrogen gas and sulfur
• Carbon dioxide and salt
• Water and oxygen

Multiple Choice

Bases react with ammonium salts to produce

• ammonia gas

• carbon dioxide and water
• metal and water
• acid and water

Multiple Choice

HCl is a strong acid because it

• Partial dissociation into ions
• No dissociation into ions
• Weak dissociation into ions
• Dissociates completely into ions

Multiple Choice

Strong acids have .................. pH values

• high
• low
• neutral
• average

Multiple Choice

What is a weak base?

• A weak base is a substance that is not basic in nature
• A weak base is a base that does not fully dissociate in a solution.
• A weak base is a base that fully dissociates in a solution
• A weak base is a strong acid

Multiple Choice

Which of the following is a weak acid?

• Sulfuric acid
• Hydrochloric acid
• Acetic acid

• Nitric acid

Multiple Choice

Amphoteric substances are

• substances that are inert
• substances that can act as both acids and bases
• substances that can only act as bases
• substances that can only act as acids

Multiple Choice

Metallic oxides are basic in nature. What name is given to metallic oxides that exhibit acidic properties?

• Amphoteric oxides
• Basic oxides
• Neutral oxides
• Acidic oxides

Multiple Select

Examples of amphoteric substances include

• Aluminum oxide

• Sodium hydroxide

• Hydrochloric acid
• Water

Multiple Select

Which of the following can be used to indicate the acidity or alkalinity of a solution?

• Litmus paper
• Methyl orange

• Methyl red

• pH scale

Multiple Choice

What are acid-base indicators used for?

• To measure temperature
• To determine the color of a solution
• To calculate the volume of a solution
• To determine the pH of a solution

Multiple Choice

What is the color of a litmus paper in a base?

• blue
• red
• green
• yellow

Multiple Choice

What is the colour of litmus paper in an HCl?

• Blue
• Red
• Green
• Yellow

Multiple Choice

What would be observed when a few drops of phenolphthalein is added to H₂SO₄?

• Colorless solution
• Green solution
• Yellow solution
• Red solution

Multiple Choice

What would happen if a few drops of methyl orange is added to NH₃ solution?

• Methyl orange will turn green.
• Methyl orange will turn yellow.
• Methyl orange will turn blue.
• Methyl orange will turn red.

Multiple Choice

What is the colour change when phenolphthalein when a few drops is added to H₃PO₄ ?

• Colorless
• Blue
• Red
• Yellow

Multiple Choice

What is a universal indicator?

• A substance that changes color in response to changes in light intensity.
• A substance that changes color in response to changes in temperature.
• A substance that changes color in response to changes in pressure.
• A substance that changes color in response to changes in pH levels.

Multiple Choice

Why is universal indicator not ideal for determining the pH of a substance?

• Universal indicator is too expensive for regular use.
• Universal indicator can only be used with acidic substances.
• Universal indicator is does not provide precise pH values.

• Universal indicator does not change color based on pH.

Multiple Choice

What colour is universal indicator in strong acids?

• Blue
• Green
• Yellow
• Red

Multiple Choice

What colour is universal indicator in strong base?

• Yellow
• Green
• Blue
• Dark purple

Multiple Choice

What would be the colour of universal indicator in water?

• Green
• Red
• Blue
• Yellow

Multiple Choice

Universal indicator is not ideal for coloured liquids because

• It only shows a limited number of colors
• It gives a broad range of colors and may not accurately represent the pH of the solution.
• It reacts unpredictably with colored substances
• It is not visible in colored solutions

Multiple Choice

Why is universal indicator not ideal for highly concentrated strong acids and bases?

• Universal indicator reacts violently with highly concentrated strong acids and bases.
• Universal indicator is too expensive for highly concentrated strong acids and bases.
• Universal indicator is not available in sufficient quantities for highly concentrated strong acids and bases.
• The pH of such substances may be out of range of the universal indicator's capacity

Multiple Choice

What is pH of a solution?

• pH of a solution is a measure of its temperature
• pH of a solution is a measure of its color
• pH is the negative logarithm of the concentration of hydrogen ions in the solution.

• pH of a solution is a measure of its volume

Multiple Choice

• A student prepares a hydrochloric acid solution by dissolving 0.025 moles of HCl in water to make a total volume of 500 mL. Calculate the pH of this solution.

• 2.5
• 0.5
• 1.8
• 1.3

Multiple Choice

• Another student prepares a sulfuric acid solution by dissolving 0.05 moles of H₂SO₄ in water to make a total volume of 250 mL. Calculate the pH of this solution.

• 0.4
• 0.7
• 0.6
• 0.5

Multiple Choice

student prepares a sulfuric acid solution by dissolving 0.05 moles of H₂SO₄ in water to make a total volume of 250 mL. Calculate the pOH of this solution.

• 13.6
• 14.7
• 10.3
• 2.5

Multiple Choice

A solution that resist change in pH when a small amount of a base or acid is added to it is known as

• Amphoteric solution

• Stable solution
• Neutral solution
• Buffer solution

Multiple Choice

What is a buffer solution?

• A buffer solution is a solution that resists changes in pH when small amounts of acid or base are added.
• A buffer solution is a solution that only reacts with acid but not with base.
• A buffer solution is a solution that has no effect on pH when small amounts of acid or base are added.
• A buffer solution is a solution that accelerates changes in pH when small amounts of acid or base are added.