Which action would a chemist most likely take to determine how the substances in a fuel affect the types of pollutants it produces when burned in
a car engine?

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds