Posted by Anonymous on .
Imagine that you have a 5.00 L gas tank and a 3.00 L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 135 , to what pressure should you fill the acetylene tank to ensure that you run out of each gas at the same time? Assume ideal behavior for all gases.

chemistry 
DrBob222,
Equation is 2C2H2 + 5O2 ==> 4CO2 + 2H2O for burning acetylene.
Use PV = nRT
Calculate n, number of moles of oxygen in the 5.00 L tank. Use any T that's convenient for both calculations (this one and the last one).
Next, convert moles oxygen to moles acetylene. Use the equation for burning acetylene in oxygen.
Now use PV = nRT again, this time for the 3.00 L tank with the new n calculated for acetylene. Post your work if you get stuck. 
chemistry 
given,
5.8