Would cgg(H2O) = x if “c0(H2O)= 0.1 mol/l” were not given, but the initial concentration c0(H2O) = 0 mol/l?

Assuming the initial concentration of water was exactly the same as that of the esters = 0 mol/l, it would then be cgg(ester) = cgg(water) = x

and in the mass action coefficient Kc then x^2 in the numerator?

I am a little confused by the cgg(water)= c0(water) + x

Is this just because we already specified an initial concentration for water on the product side? In all other calculations in class, we simply had 0 mol/l as the initial concentration for all products.

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indiachinacook
1 year ago

I don’t see how you could have expected, but your result is accurate. The equilibrium concentrations are 1-0.65=0.35 mol/l for both starting materials, 0.65 mol/l for the ester and 0.75 mol/l for water. By entering into the Mass Act

c(ester)⋅c(H2O) / c(alcohol) / c(acid) = 0.65⋅0.75/0.352 ≅4

the predetermined equilibrium constant is obtained, so it is true.

indiachinacook
1 year ago

If c1=1 mol/l is the initial concentration of alcohol and acid and c2 =0.1 mol/l is the initial concentration of H2 O, then you name the ester concentration in equilibrium simply x and starts:

K = x⋅(c2+x)/(c1−x)2

and only need to dissolve after positive x.

indiachinacook
1 year ago

Yes, of course. I did so in the denominator because the initial contracts are randomly the same.