Chemical Bonds and Reactions

Question 1

When considering inter-atomic and inter-molecular bonding (true or false):

Covalent bonds are easily broken

Answer 1

False. Covalent bonds are stronger than ionic bonds. They are found in tough materials, e.g. diamonds.

Question 2

When considering inter-atomic and inter-molecular bonding (true or false):

Hydrogen bonds require the giving up of electrons

Answer 2

False. For hydrogen bonding to take place there is usually a hydrogen atom (positively charged) covalently bound to another (negatively charged) atom.

Question 3

When considering inter-atomic and inter-molecular bonding (true or false):

Hydrophobic forces are found in lipid membranes

Answer 3

True

Question 4

When considering inter-atomic and inter-molecular bonding (true or false):

The shape of molecules is the result of many types of bond and force

Answer 4

True

Question 5

When considering inter-atomic and inter-molecular bonding (true or false):

Enzymes can break covalent bonds

Answer 5

True

Question 6

When considering the atomic structure of drugs (true or false):

Covalent bonds are only broken down in the liver

Answer 6

False. Covalent bonds are broken down wherever there are suitable enzymes present, e.g. in the liver and plasma.

Question 7

When considering the atomic structure of drugs (true or false):

Covalent bonds in drugs that are broken down in the liver always produce harmless transient substances

Answer 7

False. Some transient substances produced as a result of breaking covalent bonds, e.g. NAPQI, can cause damage in certain circumstances.

Question 8

When considering the atomic structure of drugs (true or false):

Insecticides are dangerous because of their ability to inhibit the breakdown of acetylcholine

Answer 8

True. This can cause a cholinergic crisis.

Question 9

When considering the atomic structure of drugs (true or false):

At plasma pH, drugs must be acidic in order for electrostatic binding to take place

Answer 9

False. At plasma pH, drug molecules may be acidic (proton donor, becoming negatively charged) or basic (proton acceptor, becoming positively charged). Either charge will bind to an opposite charge in the patient’s system.

Question 10

When considering the atomic structure of drugs (true or false):

Electrostatic binding takes place between drug molecules and proteins and membranes in the patient’s system

Answer 10

True