Question

You are a NASCAR pit crew member. On the day before the Daytona 500, someone ransacks your records and takes all information pertaining to your driver, Darrell Waltrip, as well as the specifics of the car. On race day Darrell is leading the race with 20 laps to go. Yeeeee haaaa!! He just finished a pit stop which included refueling to fill up his tank. You know that 25 gallons of fuel (3.5 kg) are in the tank. On the way out of the pits, Darrell radioes back to you and asks, "Am I going to have enough fuel to finish the last 20 laps of the race or am I going to have to make another pit stop?" Jeff Gordon, who is in second place also just finished a pit stop. You radio back saying, "Hang on! Let me make a few calculations and get back to you!" You whip out your calculator and begin your calculations based on your knowledge of stoichiometry. Other information you remember from the lost records is the following: • The formula for the fuel is C5H12 and it undergoes a combustion reaction in the engine of the car. • The car uses an average of 300 grams of oxygen for each lap. When you radio Darrell back, what are you going to tell him? "Go for it!" or "You'll need to come into the pits one more time! I'll warn the crew."|

Answer 1

the fuel C5H12 undergo combustion according to reaction :

C5H12 + 8 O2 = 5 CO2 + 6 H2O

now, it is given that the amount of fuel is 3.5 kg or 3500 g of C5H12 .

according to the balanced chemical equation ,

1 mole of fuel reacts with 8 moles of oxygen.

i.e 72 g of fuel reacts with ( 8 x 32 ) g = 256 g of oxygen .

now, car needs 300 g of oxygen per lap

for 20 lap , amount of oxygen needed = 300 x 20 = 6000 g

according to balanced chemical equation , 6000 g of oxygen needs 6000 x 72 / 256 = 1687.5 g of fuel

but we have 3500 g of fuel in the tank. so it will be sufficient to cover 20 laps. there is no need to refill the tank.