[White Mage]

Ammonium perchlorate, NH4ClO4, is heated above 200C, it decomposes into N2,Cl2,O2 and water vapor.

a) What total pressure of gas would be produced at 800C by igniting 7.00x10^5 kg NH4ClO4 and allowing it to expand to fill a volume of 6400m^3. Ideal gas behavior is assumed.

b)calculate the mole fraction of chlorine and it's partial pressure in the mixture of gasses produced.

c) The van der Walls equation applies only to pure gases, not mixtures. For this mixture it may still be possible to define effective a and b parameters to relate total pressure, volume, temperature, and total number of moles. Suppose the gas mixture has a=(4.00 atm)(L^2)(mol^-2) and b=0.0330 L/mol. Recalculate the pressure of the gas mixture in part a) using the van der Walls equation. Why is the result smaller than in part a)?

[GollumsLunch]

You need to start by writing the equation for the decomposition.  Based on that equation, can you determine how many moles of gas will be produced for each mole of reactant you start with?  Are you given enough information to calculate how many moles of reactant you start with?

Start with that, and let me know how you do.

[White Mage]

ok i found a) it comes out to be 41.01 atm. thanks for the help. any idea about b)?

[White Mage]

k also found b) just need c) now.

[Borek]

Write Van der Waals equation. This is simple plug and chug.