I am having the following problem: I need to calculate 2 Keq values based on the experiment that I conducted.
I reacted 0.082 moles of benzoic acid with 0.618 moles of methanol and obtained 0.055 moles of methyl benzoate.
When I calculate the first Keq based on the following equation:
((Benzoic Acid Initial - methyl benzoate) ^2) / ((Benzoic Acid I -( Benzoic Acid Initial- methyl benzoate)x (methanol - (benzoic Acid I- Methyl benzoate))
I get 0.022
For the second Keq values you swap methyl benzoate for benzoic acid final (0.019 grams - 0.000139552 moles)
....then I get 124 ...that can't be correct- especially when I'm asked if its between 1-10 and if my values agree. Help!!
To calculate the Keq values, we need to use the balanced chemical equation and the concentrations of the reactants and products.
The balanced chemical equation for the reaction is:
Benzoic acid + Methanol → Methyl benzoate + Water
Based on the information provided, we have:
Initial moles of Benzoic acid (Ba) = 0.082 moles
Initial moles of Methanol (M) = 0.618 moles
Moles of Methyl benzoate (Mb) formed = 0.055 moles
From this, we can calculate the concentrations (in moles per liter) of the reactants and products:
Initial concentration of Ba (BaI) = 0.082 moles / (volume in liters of reaction mixture)
Initial concentration of M (MI) = 0.618 moles / (volume in liters of reaction mixture)
Final concentration of Mb (MbF) = 0.055 moles / (volume in liters of reaction mixture)
To calculate the first Keq value, we can use the formula you provided:
Keq1 = ((BaI - Mb)^2) / ((BaI - Mb) * (MI - (BaI - Mb)))
Substituting the values:
Keq1 = ((0.082 - 0.055)^2) / ((0.082 - 0.055) * (0.618 - (0.082 - 0.055)))
Simplifying:
Keq1 = (0.027^2) / (0.027 * 0.591)
Keq1 = 0.729 / 0.015957
Keq1 ≈ 45.66
For the second Keq value, we substitute the moles of the final concentration of Benzoic acid (BaF) instead of Mb:
BaF = (Initial moles of Ba - moles of Mb formed) = 0.082 – 0.055 = 0.027 moles
Keq2 = ((BaF)^2) / ((BaF) * (MI - (BaF - Mb)))
Substituting the values:
Keq2 = ((0.027)^2) / ((0.027) * (0.618 - (0.027 - 0.055)))
Simplifying:
Keq2 = 0.000729 / (0.027 * 0.59)
Keq2 ≈ 44.27
Please note that the actual values may differ slightly based on the specific values used for the concentrations and the volume of the reaction mixture.
To calculate the equilibrium constant (Keq) values based on the given experimental data, you need to use the balanced chemical equation and the concentrations (or amounts) of the reactants and products.
The balanced chemical equation for the reaction between benzoic acid (C6H5COOH) and methanol (CH3OH) to form methyl benzoate (C6H5COOCH3) is:
C6H5COOH + CH3OH ⇌ C6H5COOCH3 + H2O
From the information provided, the initial amount of benzoic acid (C6H5COOH) is 0.082 moles, the initial amount of methanol (CH3OH) is 0.618 moles, and the amount of methyl benzoate (C6H5COOCH3) formed is 0.055 moles.
To calculate the first Keq value, you need to determine the concentrations of the reactants and products at equilibrium. Since benzoic acid is a weak acid, it does not dissociate significantly in water, so its concentration can be considered constant. Therefore, only the concentration of methyl benzoate (C6H5COOCH3) needs to be considered.
The initial moles of benzoic acid are 0.082 moles, and from the amount of methyl benzoate formed (0.055 moles), you can calculate the moles of benzoic acid at equilibrium by subtracting the moles of methyl benzoate formed from the initial moles of benzoic acid.
Benzoic Acid at equilibrium = Initial Moles of Benzoic Acid - Moles of Methyl Benzoate
= 0.082 moles - 0.055 moles
= 0.027 moles
Now, you can calculate the first Keq value using the formula:
Keq = [(Methyl Benzoate at equilibrium)^2] / [(Methanol at equilibrium)(Benzoic Acid at equilibrium)]
In this case, you need to calculate the concentration of methyl benzoate at equilibrium as follows:
Methyl Benzoate at equilibrium = Moles of Methyl Benzoate formed / Total Volume (assuming volume remains constant)
= 0.055 moles / Total Volume (in liters)
Next, you need to calculate the concentration of methanol at equilibrium, which can be obtained by subtracting the moles of methanol reacted from the initial moles of methanol.
Methanol at equilibrium = Initial Moles of Methanol - Moles of Methanol reacted
= 0.618 moles - 0 moles (assuming complete reaction)
= 0.618 moles
Now, plug in the values of the concentrations into the Keq expression:
Keq = [(Methyl Benzoate at equilibrium)^2] / [(Methanol at equilibrium)(Benzoic Acid at equilibrium)]
By following these steps, you should be able to calculate the correct values of Keq for your experiment.