# Chemistry Diagram

'the reaction between hydrogen and chlorine involves two gases with diatomic (two-atom) molecules. The equation for the reaction is: H2(g) + Cl2(g) --> 2HCl(g). Draw two diagrams to explain how increasing the gas pressure will increase the rate of reaction.'
I've searched for this question but can't find it anywhere help pls!
Perhaps one diagram being a container with x particles in it, and the second diagram being a smaller container with x particles in it?
Original post by grindinrevisin
'the reaction between hydrogen and chlorine involves two gases with diatomic (two-atom) molecules. The equation for the reaction is: H2(g) + Cl2(g) --> 2HCl(g). Draw two diagrams to explain how increasing the gas pressure will increase the rate of reaction.'
I've searched for this question but can't find it anywhere help pls!

It is a bit of a strange question and it is far from obvious what it actually wants from you.

If this is an A level question, I’d probably draw something similar to what Methene has described (i.e two pistons compressing a gas mixture with one piston compressing the mixture more than the other), but I’d also make sure to write a sentence along the lines of “higher pressure means less space between molecules, so more frequent, successful collisions between H2 and Cl2.”

If it weren’t asking for a pair of diagrams, I’d probably instead show that pV = nRT rearranges to n/V = p/RT (where n/V is equivalent to the concentration) and so if you change the pressure (at constant temperature), the concentration of gas also increases linearly. I’d then argue (in terms of a rate equation) that this corresponds to an increased rate of reaction.
Original post by UtterlyUseless69
It is a bit of a strange question and it is far from obvious what it actually wants from you.
If this is an A level question, I’d probably draw something similar to what Methene has described (i.e two pistons compressing a gas mixture with one piston compressing the mixture more than the other), but I’d also make sure to write a sentence along the lines of “higher pressure means less space between molecules, so more frequent, successful collisions between H2 and Cl2.”
If it weren’t asking for a pair of diagrams, I’d probably instead show that pV = nRT rearranges to n/V = p/RT (where n/V is equivalent to the concentration) and so if you change the pressure (at constant temperature), the concentration of gas also increases linearly. I’d then argue (in terms of a rate equation) that this corresponds to an increased rate of reaction.

lol i wish it was an A level question then I would have an excuse. I'm in year 9 and got this question for homework, having never seen anything really like it before, but thx, rlly helps
Original post by grindinrevisin
lol i wish it was an A level question then I would have an excuse. I'm in year 9 and got this question for homework, having never seen anything really like it before, but thx, rlly helps
God that is a daft question to ask a year 9 lol

Yeah - Methene’s answer is probably best, followed by a sentence like the one I recommended.

The pV = nRT and rate equation thing is more of an undergraduate level concept, so ignore it entirely lol.