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# Equilibrium watch

1. Hi guys,
I have one question, I think you may find it a bit silly but can anyone explain it to me pleaseee.
So:
The reversible reaction A + B --> C + D reaches the equilibrium.
At the beginning 2 moles of A and 1 mole of B are mixed.
Now my question is:
If the ratio in the equation is 1:1, how come the amounts of A and B can be different ?

Thanks
2. If you consider another (non-equilibrium) reaction:

HCl + NaOH -> NaCl + H2O

...if you started with 2 mol of HCl and 1 mol of NaOH, what would you be left with?
3. (Original post by Pigster)
If you consider another (non-equilibrium) reaction:

HCl + NaOH -> NaCl + H2O

...if you started with 2 mol of HCl and 1 mol of NaOH, what would you be left with?
Not sure
4. 1 mol of HCl would react with 1 mol of NaOH. There is 1 mol of HCl remaining, but no alkali to react with it. (1 mol of NaCl and 1 mol of H2O are made).

In your case, you started with 2 mol of A and 1 mol of B. x mol of A would react with x mol of B, leaving you with 2-x mol of A and 1-x mol of B (making x mol of C and x mol of D). What's the problem?
5. (Original post by Pigster)
1 mol of HCl would react with 1 mol of NaOH. There is 1 mol of HCl remaining, but no alkali to react with it. (1 mol of NaCl and 1 mol of H2O are made).

In your case, you started with 2 mol of A and 1 mol of B. x mol of A would react with x mol of B, leaving you with 2-x mol of A and 1-x mol of B (making x mol of C and x mol of D). What's the problem?
ok now I see, its about REACTING amounts. Makes sense.
Thank you a lot

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Updated: January 11, 2017
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