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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: el123 on April 11, 2010, 08:16:54 PM

Title: Direction of reaction.
Post by: el123 on April 11, 2010, 08:16:54 PM
At approx 430 degree celcius the equilibrium constant k=50 for the reaction
H2(g) + I2(g) <----> 2HI(g)

A gas mixture is prepared consisting of hydrogen , iodine and hydrogen iodide at partial pressures of 0.50atm , 0.01 atm and 0.50atm respectively.
Will the spontaneous reaction be from left to right or from right to left.

So i got stuck on this , thought i had it but just want some reassurancce to see if i get this.

0.502/0.50*0.01   = 50
Qp=K so therefore reaction is at equilibrium.

Is the above correct. if no can you please explain what ive done wrong.

What would be the spontaneous reaction direction if all three gases had equal partial pressures??

0.502/0.50*0.50 = 1     
Qp<K    so reaction goes from right to left.


Is that right?

Any help is appreciated.


Title: Re: Direction of reaction.
Post by: Matias Ekstrand on April 12, 2010, 12:22:10 AM
When Q < K, reaction goes from left to right. Otherwise it's correct.