Question 1. A needle can be made to "float" on the surface tension of water. What causes this surface tension to form?
The adhesion of water molecules to the needle
The heat capacity of water
The cohesion of water molecules to each other
The solubility of water
Question 2. How do buffers minimize change in the pH of biological systems?
By donating H+ ions when there is a shortage
By absorbing H+ ions when there is an excess
Both of these
Neither of these
Question 3. One of the four properties of water is
insulation
polarity
moderates temperature
water is a solute
Question 4. Select the most complete explanation of what the pH scale actually measures.
The concentration of hydrogen ions in a solution
The concentration of hydroxide ions in a solute
The alkalinity of a solvent
The acidity of a solvent
Question 5. Something with a pH of 5 would be ________.
acidic
alkaline
neutral
basic
Question 6. The difference in pH units between two acidic solutions is three. How much more acidic is the stronger acid than the weaker acid?
3 times more acidic
100 times more acidic
30 times more acidic
1,000 times more acidic
Question 7. 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.
Polyester is more flexible than cotton.
Polyester fibers are thinner than cotton fibers.
Polyester is not a naturally occurring substance, whereas cotton is a naturally occurring substance.
Question 8. Water is the lightest (least dense) when it ________.
freezes
is just below boiling
is at room temperature
is just above freezing
Question 9. We are about 75% water
True
False
Question 10. 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 hydrogen.
Uneven sharing of electron pairs occurs due to the strong pull of oxygen.
Hydrogen donates its electrons to oxygen.
Oxygen donates its electrons to hydrogen.