Chem, could someone cheak my work please.

I did this experiment where I filled a graduated cylinder with water. The I put a stopper on it and put it under water and removed the stopper. The with a modified lighter (that wouldn't release sparks) I added butane gas. I got the following results:

mass of lighter = 15.18 g
final mass of lighter = 15.00 g
volume of butane = 80.0 mL
temperature = 25.0 degrees celsius
atmosperic pressure = 101.4 Kpa

1) What would the mass of butane be?
0.18 grams

2) Number of mols of butane?
0.003170846 mol.

3)Molar mass of butane?
56.8 g/mol

3) Calulate the volume of the number of moles found in questin 2 of butane at STP then use that value to find density. I don't know how to do this at all. ???

asked by Lena
  1. Ok, for 3) you need the volume of butane you measured, and the pressure of that butane. The pressure of the butane is atmospheric minus water vapor pressure (there is water vapor in there).

    You get the water vapor pressure from a water vapor pressure table, knowing the temperature.

    Then, you have volume, pressure, and number of moles. Now correct it to stp

    PV=nRT and (letting small letters meaning your conditions, capital letters at stp)
    pv=nRt

    dividing the first equation by the second

    PV/pv=T/t
    and you are solving for V
    V=pvT/Pt

    density at stp

    V/massbutane

    posted by bobpursley
  2. Isn't the density the mass of butane/V
    ?

    posted by Lena
  3. yes, you are correct, I was in too much of a hurry. Correct that.

    posted by bobpursley

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chem

    I did this experiment where I filled a graduated cylinder with water. The I put a stopper on it and put it under water and removed the stopper. The with a modified lighter (that wouldn't release sparks) I added butane gas. I got
  2. Chemistry

    You put a rock weighing 45g into a graduated cylinder. Before you put the rock in the graduated cylinder, the volume of water in the cylinder is 10mL. After you put the rock in the graduated cylinder, the volume rises to 25mL.
  3. chemistry

    a student weighs out 37.0 grams worth of an unknown liquid into her graduated cylinder while preparing an experiment. Her formerly empty 100 mL graduated cylinder now contains exactly 25mL of liquid. She then adds 3.25 ml of H2O
  4. Chemistry

    A graduated cylinder contains 56.3ml of water. A metal cylinder is dropped in the water and is completely covered by water. The diameter of the cylinder is 3.8 cm and the height of the cylinder in 5.4cm. What is the volume reading
  5. math

    This is the Crailsheim water tower in Baden-W├╝rttemberg, Germany. Its construction was completed in 1912. The base of the tower is a graduated cylinder about 19.2 m high with a diameter of 11.5 m at the base and 8.1 m at the top.
  6. Science

    How can a graduated cylinder marked in milliliters be used to measure the volume of a small wooden block? Hurry up and answer this for me!!!!!! put 100ml water into the cylinder, then put the block into the water and measure how
  7. physics

    A graduated cylinder is inverted in a very large bucket of water. The depth of the water in the container is 6 m and the top of the bucket is open to the air in the room. The mouth (bottom) of the graduated cylinder is 4 m above
  8. biology

    Susan needs to measure and heat the chemical she wants to use in an experiment with a graduated cylinder. Which graduated cylinder is suitable for use?
  9. chemistry help ASAP

    a graduated cylinder contains 20.0 ml of water. when 100.g of a brass cylinder were added to the graduated cylinder, the water level rose to 32.6 ml. given this information what is the density of the brass cylinder?
  10. chemistry

    1a. You fill a small graduated cylinder with exactly 10.00 ml of distilled water with a temperature of 20.0oC which weighs 10.00 grams. You pour out the water and put in 10.00 ml of ethanol into the same graduated cylinder which

More Similar Questions