General Chemistry 2 Quiz

What is the definition of an acid according to the Bronsted – Lowry terminology?

• A substance that releases hydrogen gas

• A substance that accepts protons

• A proton donor (H+)

• A substance that releases hydroxide ions

Answer explanation

According to the Bronsted – Lowry terminology, an acid is defined as a proton donor (H+), making the correct choice the one stating 'A proton donor (H+).'

In the Bronsted-Lowry theory, what is defined as a proton acceptor?

• Conjugate base

• Conjugate acid

• Base

• Acid

Answer explanation

In the Bronsted-Lowry theory, a proton acceptor is defined as a conjugate acid, which is a species that gains a proton in a chemical reaction.

What is the conjugate acid in a Bronsted-Lowry acid-base reaction?

• The species formed after the base accepts a proton

• The species formed after an acid donates its proton

• The species formed after the acid accepts a proton

• The species formed after the base donates a proton

Answer explanation

The conjugate acid is formed after an acid donates its proton in a Bronsted-Lowry acid-base reaction.

Which of the following reactions involves NH3 acting as a weak Bronsted – Lowry base?

• HSO3- + CN- ↔ HCN + SO32-

• H3O+ + PO43- ↔ HPO42- + H2O

• NH3 + HI ↔ NH4+ + I-

• NH4+ + HS- ↔ NH3 + H2S

Answer explanation

The correct reaction involving NH3 as a weak Bronsted – Lowry base is NH4+ + HS- ↔ NH3 + H2S.

What ion is produced when water molecule donates its proton?

• H+

• OH-

• H3O+

• H2O

Answer explanation

When a water molecule donates its proton, it forms the hydroxide ion (OH-), making it the correct choice in this case.

What happens to water molecules if it accepts a proton?

• It becomes a Bronsted-Lowry acid

• It becomes a Bronsted-Lowry base

• It becomes a positively charged ion

• It becomes a neutral molecule

Answer explanation

When water accepts a proton, it acts as a Bronsted-Lowry base by gaining a proton to form a hydronium ion.

What is produced when hydronium ion, H3O+, donates its proton?

• Hydrogen gas, H2

• Hydrogen ion, H+

• Hydroxide ion, OH-

• Water, H2O

Answer explanation

When hydronium ion, H3O+, donates its proton, it forms water, H2O. This is because the hydronium ion is a water molecule with an extra proton, so when it donates the proton, it becomes a water molecule.

Which of the following is an example of a weak base?

• Hydrochloric acid, HCl

• Sodium hydroxide, NaOH

• Ammonia, NH3

• Sulfuric acid, H2SO4

Answer explanation

Ammonia, NH3, is an example of a weak base due to its ability to accept protons and form ammonium ions in solution.

In the Bronsted-Lowry theory, what is defined as a proton donor?

• Conjugate base

• Conjugate acid

• Base

• Acid

Answer explanation

In the Bronsted-Lowry theory, a proton donor is defined as an acid, which donates a proton to another species.

What is the conjugate base of H3PO4?

• H3O+

• PO43-

• HPO42-

• H2PO4-

Answer explanation

The conjugate base of H3PO4 is H2PO4- because it is formed by removing one proton (H+) from H3PO4, leaving behind H2PO4-.