Biol 1406 - Chapter 3, Water and Life

One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?

10,000 times more.

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?

A hydrogen bond.

Which of the following effects is produced by the high surface tension of water?

A water strider can walk across the surface of a small pond.

Buffers are substances that help resist shifts in pH by?

Both donating H+ to a solution when bases are added, and accepting H+ when acids are added.

Water molecules are able to form hydrogen bonds with?

Compounds that have polar covalent bonds..

If the pH of a solution is decreased from 9 to 8, it means that the?

Concentration of H+ has increased tenfold (10X) and the concentration of OH- has decreased to one-tenth (1/10) what they were at pH 9..

If the pH of a solution is increased from pH 5 to pH 7, it means that the

Concentration of OH- is 100 times greater than what it was at pH 5.

The bonds that are broken when water vaporizes are?

Hydrogen bonds between water molecules..

Why does ice float in liquid water?

Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

It is a strong acid that ionizes completely in water..

Hydrophobic substances such as vegetable oil are

Nonpolar substances that repel water molecules..

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by?

Polar covalent bonds..

Increased atmospheric CO2 concentrations might have what effect on seawater?

Seawater will become more acidic, and carbonate concentrations will decrease..

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

The absorption of heat by the breaking of hydrogen bonds.

The partial negative charge in a molecule of water occurs because

The electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus.

Which of the following statements is true about buffer solutions?

They maintain a relatively constant pH when either acids or bases are added to them.

Research indicates that acid precipitation can damage living organisms by?

Washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth.

Which of the following is a hydrophobic material?

Wax.