Let's analyze each question and provide the answers:
-
Which of these characterizes organic compounds?
- The only statement that characterizes organic compounds accurately is: They are compounds containing carbon.
-
Which of these statements is FALSE?
- The statement that is FALSE is: Fire caused by kerosene can be put out if water is poured into the fire. (This is false because water can spread a kerosene fire due to its lower density.)
-
In which of the following medium would sound waves travel the fastest?
- Sound waves travel fastest in: Solids. (Sound travels fastest in solids due to closely packed molecules that facilitate quicker vibrations.)
-
Which of the following is heterogeneous?
- The heterogeneous mixture is: Sea water. (Sea water contains various dissolved salts and other materials making it non-uniform.)
-
Why should gasoline be stored in tightly covered narrow-mouthed containers and should be placed away from heat?
- The primary reasons are: To reduce evaporation and To decrease its potential as a fire hazard.
Thus, the best answer to the last question is: I and II.
To summarize:
- Organic compounds are characterized by containing carbon.
- The false statement is about fire and water with kerosene.
- Sound travels fastest in solids.
- Sea water is heterogeneous.
- Gasoline should be carefully stored to reduce evaporation and minimize fire hazards (I and II).