AS Edexcel Chemistry Question

I am confused by the answer to a question in the June Unit 2 Paper 1R, can anyone help explain it?

a) is easy, and so should be b), but apparently according to the mark scheme the answer to b) is D, why?
The number of molecules on both sides of the equation are equal?

(edited 9 years ago)

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Reply 1

RandomStudent97

Original post by DesignPredator

I am confused by the answer to a question in the June Unit 2 Paper 1R, can anyone help explain it?

a) is easy, and so should be b), but apparently according to the mark scheme the answer to b) is D, why?
The number of molecules on both sides of the equation are equal?

Decreasing the volume would increase the pressure and therefore the rate of reaction would increase so more product would be formed.

Reply 2

DesignPredator

Original post by RandomStudent97

Decreasing the volume would increase the pressure and therefore the rate of reaction would increase so more product would be formed.

But it is an equilibrium reaction, increasing pressure should not effect the position of equilibrium as there are equal numbers of gaseous molecules on both sides. Reaction rate in forward and backwards reaction should be the same.

Reply 3

yasmin#2

Original post by DesignPredator

I am confused by the answer to a question in the June Unit 2 Paper 1R, can anyone help explain it?

a) is easy, and so should be b), but apparently according to the mark scheme the answer to b) is D, why?
The number of molecules on both sides of the equation are equal?

not too sure but this is my opinion on the Q

for b) the compressing means that there will be less distance between the gas particles (higher pressure) and so a higher likelihood of collisions and therefore a higher likelihood of successful collisions.

more iodine is produced because of more successful collisions making the solution a darker purple, this then eventually adjusts to equilibrium again and goes back to the colour it was originally.The question was asking what happens immediately -this is before the system reaches equilibrium.