Butane Lab (R) Name_______________________pd_____
Purpose: Collect butane, observe properties, use measurements to calculate density and moles of butane.
Procedure:
1. mass dry lighter
2. collect gas as demonstrated
3. dry lighter as demonstrated, remass
4. bring butane to fume hood as demonstrated, clean up
Data: Use data on video if you missed the lab
1. mass before _____g
2. mass after _______g
3. volume of butane _____mL = _____L
4. temperature of butane (same as water) ______ C = _______K
5. pressure (read barometer at black needle; the gold needle is a marker that can be set so daily change can be seen) _______ cm Hg = _______ mm Hg
6. ideal gas law constant ‘R’ from p 384 (e364)
7. Do we have mercury in our class thermometers? How can you tell?
8. .Look at the wooden weather instrument at the pope's desk. What is pressure in inches of Hg? What is weather prediction according to barometer?
skip What is humidity today? What is the cause of humidity?
Calculations:
1. mass of butane = ________g
2. density of butane = ___________g/mL
3. molar mass of butane = ____________g/mole
4. moles of butane in lab (mass/molar mass) _______ / _______ = _________ mole
5. .pressure of the dry butane (use dalton’s law) _________________ mmHg
6. moles of butane using # 3, 4, 5 from the data and the ideal gas law (PV=nRT) _____________
Conclusions:
1. Are calculations #4 & 6 close? ______ Which do you think is the most accurate? _______ Why?_____________________________________________________________
2. skip Why did we have to find the pressure of ‘dry’ butane?__________________________
3. What can cause a mistake in this lab?_____________________________________________
4. 3 properties of butane are __________________, ________________ and ________________
5. Is butane more or less dense than air? ______________ What is your evidence?_______________________________________________________________
6. The butane is in the _________ state inside the lighter, but in the ___________ state outside the lighter because _________________________________________________________
7. What does the word volatile mean? _______________________________________________
8. Rank water, butane, oil, salt from most to least volatile.
9. The common name of the black smoke is ___________, and it is made of the element _________.
10. Butane __________ (is or isn’t) soluble in water. The evidence is______________________________________________________________
11. Butane, propane and methane are all alike because_____________________________________________________, but they are different because___________________________________________________________________________
12. Write a balanced chemical equation for the combustion of butane, then calculate the a. volume of Carbon dioxide and the b. mass of water produced from the butane burned.
(for calculating volume, use 1mole of gas at STP = 22.4L) fill in form.
13 a. suppose there were 50g of butane and 100g of oxygen, what mass of water could be obtained? b. How much of the excess reactant remains? ( rchem use 100g of butane and unlimited oxygen and do not answer b)