Question

An experiment is set up with a glass bottle and a candle. The starting volume of the bottle is 250 mL at a pressure of 1 atm. The bottle contains 0.00600 moles of O2 gas. A candle is then put into the bottle and the flame consumes most of the oxygen. The temperature is 70°C. After the candle goes out, there is only 0.000540 moles of oxygen remaining and the temperature drops to 35°C. Assume the volume is still 250 mL. What is the pressure inside the bottle?

________atm (use 3 sig figs with one zero in front of the decimal)


30 points

Answer 1

Answer: 0.112 atm.

Explanation:

(PV = nRT), which states that the pressure times volume of a gas is equal to the number of moles of gas times the ideal gas constant times the temperature.

Since the volume of the bottle is constant, we can rearrange the Ideal Gas Law to solve for pressure:

P = (nRT) / V

where

n = 0.000540 moles (the amount of O2 remaining after the candle goes out)

R = 8.31 J/mol*K (the ideal gas constant)

T = 35 + 273 = 308 K (the temperature in kelvins)

V = 250 mL = 0.25 L (the volume of the bottle in liters)

Plugging in the values, we get:

P = (0.000540 * 8.31 * 308) / 0.25

P = 0.112 atm

So, the pressure inside the bottle after the candle goes out is approximately 0.112 atm.