Question 1

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

Accepted Answer

The bolded compound (H₃) has a hydrogen ion that can be donated, making it an acid. The reaction shows that it donates the hydrogen ion to form H₃O⁺, indicating it behaves as an acid in this reaction.

Question 2

Which of the following compounds would least likely act as an acid?

Accepted Answer

The compound A is a sulfonate ion, which is a strong base and thus least likely to act as an acid. The other compounds contain hydrogen atoms that can potentially act as acidic protons.

Question 3

What is a base?

Accepted Answer

A base is defined as a substance that accepts a hydrogen ion (H+) according to the Brønsted-Lowry theory.

Question 4

According to the following reaction,which molecule is acting as a base? H₂O + NH₃ → OH^- + NH₄⁺

Accepted Answer

In this reaction, NH₃ is donating a proton (acting as an acid) to H₂O, which accepts the proton (acting as a base). Therefore, NH₃ is the molecule that is acting as an acid, and H₂O is the molecule that is acting as a base.

Question 5

In the reaction below,what does the symbol ⇌ mean? OH^- + NH₄⁺ ⇌ H₂O + NH₃

Accepted Answer

The symbol ⇌ represents a reversible reaction, meaning that both the forward and backward reactions are happening at the same time, leading to an equilibrium state.

Question 6

For the following acid-base reaction,identify which salt is formed. HCl + NaOH ⇌ ???? + H₂O

Accepted Answer

When hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the acid-base neutralization forms water (H2O) and sodium chloride (NaCl) as the salt.

Question 7

How do you make a proton out of a hydrogen atom?

Accepted Answer

A hydrogen atom consists of one proton and one electron. Removing the electron leaves only the proton, which is a subatomic particle with a positive charge and is commonly known as a proton.

Question 8

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

Accepted Answer

The bolded compound (H₃) has a hydrogen ion that can be donated, making it an acid. The reaction shows that it donates the hydrogen ion to form H₃O⁺, indicating it behaves as an acid in this reaction.

Question 9

According to the following reaction,which molecule is acting as a base? H₃O⁺ + HSO₄^- → H₂O + H₂SO₄

Accepted Answer

In the reaction, HSO₄^- accepts a proton from H₃O⁺, indicating it is acting as a base. Therefore, the correct choice is D, HSO₄^-.

Question 10

According to the following reaction,which molecule is acting as an acid? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

Accepted Answer

In the reaction, the molecule H₂SO₄ is donating a proton (H+) to the molecule H₂O. This means that H₂SO₄ is acting as an acid, as it is donating a proton.

Question 11

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

Accepted Answer

The compound in bold, H₃O, is accepting a proton (H+) from H₂O, indicating it is behaving as a base.

Question 12

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

Accepted Answer

The compound in bold, H₃PO₄, is acting as a base because it is accepting a proton (H+) from the other molecule in the reaction, H₂O. This can be seen by the arrows pointing towards the compound in bold, indicating protonation. Therefore, the answer is A) acid.

Question 13

According to the following reaction,which molecule is acting as an acid? H₃O⁺ + HSO₄^- → H₂O + H₂SO₄

Accepted Answer

The molecule acting as an acid is the one donating a proton (H+), which in this case is H₃O⁺, as it loses a hydrogen to form H₂O.

Question 14

According to the following reaction,which molecule is acting as a base? OH^- + NH₄⁺ → H₂O + NH₃

Accepted Answer

In the reaction, NH acts as an acid by donating a proton to the O in OH^-. Therefore, OH^- acts as a base by accepting the proton.

Question 15

According to the following reaction,which molecule is acting as an acid? H₂O + NH₃ → OH^- + NH₄⁺

Accepted Answer

In the reaction, H₂O donates a proton (H+) to NH₃, making it the base. Therefore, H₂O is the acid.

Question 16

What best describes what happens when an acid such as HCl is mixed with water?

Accepted Answer

When HCl is mixed with water, the hydrogen ion (proton) chemically bonded to the chlorine is transferred to a water molecule, forming a hydronium ion (H3O+) and a chloride ion (Cl-). This is the process of dissociation or ionization of the acid in water.

Question 17

According to the following reaction,which molecule is acting as a base? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

Accepted Answer

In the reaction, H₂O accepts a proton (H⁺) from H₂SO₄, forming H₃O⁺, thus acting as a base.

Question 18

According to the following reaction,which molecule is acting as an acid? OH^- + NH₄⁺ → H₂O + NH₃

Accepted Answer

The molecule NH₄⁺ is acting as an acid because it donates a hydrogen ion (H+) to the other reactant, resulting in the formation of NH₃.

Question 19

What is an acid?

Accepted Answer

An acid is defined as anything that donates hydrogen ions, also known as protons. This is the definition accepted by the majority of scientists and is part of the Brønsted-Lowry theory of acids and bases. Choice B is incorrect because accepting hydrogen atoms does not necessarily make an entity an acid; it could also be a reducing agent. Choice C is incorrect because donating hydrogen atoms is not a common feature of acids. Choice D is incorrect because dissolving metals does not require the presence of an acid, although acids can certainly dissolve some metals. Choice E is incorrect because hydronium ions are simply hydrated hydrogen ions, so this definition is essentially the same as choice A.

Question 20

For the following acid-base reaction,identify what compound is formed in the space marked. HCl + KOH ⇌ ???? + H₂O

Accepted Answer

The reaction between HCl (hydrochloric acid) and KOH (potassium hydroxide) is a neutralization reaction that produces KCl (potassium chloride) and water (H2O). The correct product for the space marked is KCl, as it is the salt formed from the reaction.

Quiz 18: Two Classes of Chemical Reactions

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

Which of the following compounds would least likely act as an acid?

What is a base?

According to the following reaction,which molecule is acting as a base? H2O + NH3 → OH- + NH4+

In the reaction below,what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3

For the following acid-base reaction,identify which salt is formed. HCl + NaOH ⇌ ???? + H2O

How do you make a proton out of a hydrogen atom?

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

According to the following reaction,which molecule is acting as a base? H3O+ + HSO4- → H2O + H2SO4

According to the following reaction,which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

According to the following reaction,which molecule is acting as an acid? H3O+ + HSO4- → H2O + H2SO4

According to the following reaction,which molecule is acting as a base? OH- + NH4+ → H2O + NH3

According to the following reaction,which molecule is acting as an acid? H2O + NH3 → OH- + NH4+

What best describes what happens when an acid such as HCl is mixed with water?

According to the following reaction,which molecule is acting as a base? H2O + H2SO4 → H3O+ + HSO4-

According to the following reaction,which molecule is acting as an acid? OH- + NH4+ → H2O + NH3

What is an acid?

For the following acid-base reaction,identify what compound is formed in the space marked. HCl + KOH ⇌ ???? + H2O

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

According to the following reaction,which molecule is acting as a base? H₂O + NH₃ → OH^- + NH₄⁺

In the reaction below,what does the symbol ⇌ mean? OH^- + NH₄⁺ ⇌ H₂O + NH₃

For the following acid-base reaction,identify which salt is formed. HCl + NaOH ⇌ ???? + H₂O

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

According to the following reaction,which molecule is acting as a base? H₃O⁺ + HSO₄^- → H₂O + H₂SO₄

According to the following reaction,which molecule is acting as an acid? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

For the following reaction,identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

According to the following reaction,which molecule is acting as an acid? H₃O⁺ + HSO₄^- → H₂O + H₂SO₄

According to the following reaction,which molecule is acting as a base? OH^- + NH₄⁺ → H₂O + NH₃

According to the following reaction,which molecule is acting as an acid? H₂O + NH₃ → OH^- + NH₄⁺

According to the following reaction,which molecule is acting as a base? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

According to the following reaction,which molecule is acting as an acid? OH^- + NH₄⁺ → H₂O + NH₃

For the following acid-base reaction,identify what compound is formed in the space marked. HCl + KOH ⇌ ???? + H₂O