Cracking the SAT Chemistry Subject Test

PRACTICE TEST 1 EXPLANATIONS

Part A

1. A When we talk about specific heat, we’re talking about the amount of
   heat necessary to produce a change in temperature. The calorimeter can
   be used to measure heat input or output, and the thermometer, choice (A),
   would be used in combination with it to ascertain the associated change
   in temperature.


2. E A graduated cylinder can be used to help find the volume of an
   irregularly shaped solid. How? Fill the graduated cylinder with water, and
   read the water’s volume. Next, add the solid. The difference between the
   volume of both the water and solid and the volume of the water alone is
   the volume of the solid.


3. D When an acid and base are combined, think titration, and when you
   consider titration remember that a buret is typically used to deliver small
   amounts of acid into a base and vice versa.


4. C Electrons travel from the anode to the cathode in an electrochemical cell.
   But what allows the redox reaction to go on by maintaining charge
   neutrality in each vessel? That’s the function of a salt bridge. The salt
   bridge completes the circuit of the electrochemical cell.


5. B An amphoteric molecule can act either as an acid or a base. Proteins are
   polypeptides made from amino acids, and all amino acids have both an
   acid group (carboxylic acid group) and a base group (amino group).
   Therefore, proteins are always amphoteric.


6. C Proteins and carbohydrates are both polymers; however, only
   carbohydrates commonly form branched polymers. Glycogen and
   cellulose are both carbohydrate polymers made up of glucose monomers;
   glycogen is a highly branched polymer while cellulose is primarily
   straight-chained.