Ideal Gas Lab with Butane
Materials:
Plastic storage box
250 mL graduated cylinder
Butane lighter
Thermometer
Procedure:
1. If the plastic storage container is not about ¾
full of water, then add any necessary water.
Place the thermometer completely into the
water, allowing it to rest at the bottom.
2. Be sure the lighter is dry. Find the mass of the
lighter to the hundredths place. Record this in
the data table.
3. Completely fill the graduated cylinder with water so that there are NO air bubbles.
Carefully invert it in the plastic storage box keeping the mouth of the graduated cylinder
below the water level. If there are any air bubbles, then dump out the water and try
again.
4. Holding the butane lighter below the water level, carefully release the butane gas by
pressing the lever and catch all the gas into the graduated cylinder. Release enough gas
to fill the graduated cylinder to about the 247 mL mark.
5. Remove the lighter from the water, dry it thoroughly, and find the mass to the hundredths
place. Record this in the data table.
6. Adjust the height of the graduated cylinder in the plastic storage container so that the
water level inside the graduated cylinder lines up with the water level in the plastic
storage container (see illustration below). At this point the pressure inside the graduated
cylinder is equal to the pressure on the water in the storage container. Measure the
volume of the gas in the graduated cylinder to the tenths place. Record this in the data
table.
7. Remove the graduated cylinder from the water and stand it up to dry. Unless instructed
otherwise, keep the water in the plastic storage container.
8. Record the water temperature using the thermometer in the plastic storage container and
the atmospheric pressure provided in the data table.
Analysis:
Initial mass of the lighter
Final mass of the lighter
Mass of the butane released during the
experiment (Initial-Final)
Volume of butane released during the
experiment (collected in the graduated cylinder)
Volume of butane released in Liters
Atmospheric Pressure (provided)
Temperature of the water
Temperature of the water in Kelvins
Water vapor pressure (from water vapor
pressure table)
Pressure of the dry butane (Atmospheric
pressure – water vapor pressure)
1. Starting with PVM = mRT, rewrite the equation solving for M. Then input the data
from the data table above and calculate the molar mass for butane. Show your work and
use significant digits.
2. Butane’s actual formula is C4H10. Calculate the actual molar mass for butane to the
hundredths place.
3. Determine the percent error for your calculation of butane’s mass. Show your work
and use significant digits.
4. This technique is not appropriate for collecting all gasses for measurement. What
could happen to the gas as it leaves the lighter and gets trapped in the cylinder that would
decrease the amount of gas trapped? Answer in at least one complete sentence.