Biol 1408 Quiz 4

Something with a pH of 5 would be

acidic

How do buffers minimize change in the pH of biological systems?

Both of these

A needle can be made to "float" on the surface tension of water. What causes this surface tension to form?

The cohesion of water molecules to each other.

Select the most complete explanation of what the pH scale actually measures.

The concentration of hydrogen ions in a solution.

We are about 75% water.

True

The difference in pH units between two acidic solutions is three. How much more acidic is the stronger acid than the weak acid?

1,000 times more acidic

Water "beads up" on synthetic fabric like polyester but binds to cotton. What is the most likely explanation for this?

Polyester is nonpolar, whereas cotton is polar.

Why is one side of a water molecule partially negative while the other side is partially positive?

Uneven sharing of electron pairs occurs due to the strong pull of oxygen.

Water is the lighest (least dense) when it ___.

freezes

One of the four properties of water is

regulates temperature