Sample Questions

What determines the cohesiveness of water molecules?

a. hydrogen bonds

Which of the following is LEAST affected by the presence of water?

a. nonpolar covalent bond.

Sweating is a useful cooling mechanism for humans because water

a. takes up a great deal of heat in changing from its liquid state to its gaseous state

Milk of magnesia is often used to treat stomach upset. Is has a pH of 10. Based on this information, milk of magnesia

b. is a base

Which of the following results from an unequal sharing of electrons between atoms?

b. polar covalent bond

The human body must maintain a constant pH. In the blood, bicarbonate serves as a _____ to help maintain the necessary pH.

buffer

water molecules are cohesive because they

c. form hydrogen bonds

In general, a substance that carries an electrical charge can dissolve in water. Given this fact, which of the following would most likely NOT dissolve in water?

c. nonpolar molecules

What happens when hydrochloric acid (HCl) dissociates in pure water?

c. the HCL molecules separate into H+ and Cl- ions

For ice to melt, it has to

d. absorb heat from its surroundings

Which of the following best explains the attraction of water molecules to each other?

d. electron-proton interaction

Which of the following properties of water enables it to function as a regulator of temperature living organisms?

d. high specific heat and low heat of vaporization

Which of the following best explains the attraction of water molecules to each other?

d. hydrogen bonds

What is meant by the statement that water has a high specific heat?

d. it can absorb a lot of energy without changing temperature

If you place a paper towel in a dish of water, the water will

d. move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other

The fact that salt dissolves in water is best explained by the

d. polar nature of water molecules

If you pace a feather on the surface of a bowl of water, the feather remains suspended on the surface due to the

d. surface tension of the water

An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH3), which of the following best describes the electrical charge of the individual atoms?

d. the nitrogen is slightly more negative

hydrophilic molecules

e. readily dissolve in water