1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Reactions that produce harmless gas

  1. Mar 21, 2009 #1
    What reactions with easily obtainable reactants produce large amounts of harmless gas?

    We want to make latex or rubber balloons that inflate by themselves. We would also like to reduce the amount of liquid or solid products left in the balloon, if possible.

    Thanks!
     
  2. jcsd
  3. Mar 22, 2009 #2
    Vinegar and baking soda make carbon dioxide, which is harmless at small quantities. There is probably something better, but that's the first one that popped into my head.
     
  4. Mar 22, 2009 #3

    Borek

    User Avatar

    Staff: Mentor

    Perhaps something with a very low boiling point, that will evaporate once the balloon gets heated to the room temperature?
     
  5. Mar 22, 2009 #4
    I don't think Vinegar and baking soda in small quantities are enough to blow up a balloon. I was thinking more along the lines of dry ice + water, but don't know if that will work. and dry ice itself is too cold anyway. the ideal solution would be a fairly slow chemical reaction that start with a bit of reactants and end up producing lots of gas.
     
  6. Mar 23, 2009 #5

    Borek

    User Avatar

    Staff: Mentor

    I doubt you will find something like that (working in terms of chemical reaction). My first idea was dry ice as well.
     
  7. Mar 23, 2009 #6
    Well, baking soda is sodium bicarbonate (NaHCO3) with a molar mass of 84.007 g/mol. Vinegar is acetic acid (CH3COOH) with a molar mass of 60.05 g/mol. Each molecule of sodium bicarbonate give one molecule of CO2 with a molar mass of 44.0095 g/mol and density of 1.98 g/L as a gas.

    So you need 1.98 grams of CO2 for a liter of gas. This is 0.045 mols, which would mean 2.7g of acetic acid, and 3.78g of sodium bicarbonate. There would also be 3.7g of sodium acetate, and 0.81g of water left over. I'd guess a party balloon is about 4 liters, so you'd need about 10g acetic acid, and 15g sodium bicarbonate. I'm not sure how pure sodium bicarbonate baking soda is, or the same for vinegar. If you were looking to do this commercially though you could get them both in bulk.
     
  8. Mar 23, 2009 #7

    alxm

    User Avatar
    Science Advisor

    I'd go with just dry ice, really. You need so little that you probably won't need to worry about either the cold, or use water to get it to sublimate faster.
     
  9. Mar 23, 2009 #8

    Borek

    User Avatar

    Staff: Mentor

    The only thing I am not sure about dry ice is whether it will not do damage to the balloon, especially if allowed to contact it directly. It will cool down the surface making it loose its elasticity and being more prone to rupture. Could be that's not an issue.
     
  10. Mar 23, 2009 #9

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I wonder what the shelf life would be for this propellant?

    There has to be a relatively safe azide that you can try. I don't know of any but a sufficiently bulky one should be fairly stable and generate enough N2 to inflate the balloon.

    It seems like a lot of work and danger to do such a simple thing, though.
     
  11. Oct 27, 2009 #10
    clorox bleach and tin foil.
     
  12. Oct 27, 2009 #11

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hydrogen is NOT a harmless gas.
     
  13. May 9, 2010 #12
    i used NaHCO3 and HCL and it inflated a 1 quart ziploc bag pretty well
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Reactions that produce harmless gas
Loading...