In making the ester methyl salicylate, mathanol is reacted with salicylic acid. If 2 grams of salicylic acid is reacted with excess methanol, what mass of ester would you expect to achieve theoretically.. show work
1. Write the equation and balance it. I think everything is 1:1:1:1
2. Convert 2 g SA to moles. moles = grams/molar mass
3. using the coefficients in the balanced equation, convert moles SA to moles of the product. I think with everything being 1:1 that no conversion is needed.
4. Convert moles of the product to grams of the product. g = moles x molar mass. This is the theoretical yield.
To calculate the theoretical yield of the ester methyl salicylate, we need to determine the limiting reactant between methanol and salicylic acid. The limiting reactant is the one that is completely consumed and determines the maximum amount of product that can be formed.
Firstly, we need to determine the molar masses of the methanol (CH₃OH) and salicylic acid (C₇H₆O₃).
Methanol (CH₃OH):
C: 12.01 g/mol
H: 1.01 g/mol x 4 = 4.04 g/mol
O: 16.00 g/mol
Total: 12.01 + 4.04 + 16.00 = 32.05 g/mol
Salicylic acid (C₇H₆O₃):
C: 12.01 g/mol x 7 = 84.07 g/mol
H: 1.01 g/mol x 6 = 6.06 g/mol
O: 16.00 g/mol x 3 = 48.00 g/mol
Total: 84.07 + 6.06 + 48.00 = 138.13 g/mol
Next, we need to calculate the number of moles of salicylic acid used. We can use the formula:
moles = mass / molar mass
moles of salicylic acid = 2 g / 138.13 g/mol ≈ 0.014 moles
Since methanol is the excess reactant, it will not be fully consumed. The balanced chemical equation for the reaction is:
C₇H₆O₃ + CH₃OH → C₈H₈O₃ + H₂O
From the balanced equation, we can see that 1 mole of salicylic acid reacts with 1 mole of methanol to produce 1 mole of methyl salicylate.
Therefore, the molar ratio of salicylic acid to methyl salicylate is 1:1.
Therefore, the moles of methyl salicylate formed will also be approximately 0.014 moles.
Finally, we can calculate the mass of the ester using the formula:
mass = moles × molar mass
mass of ester = 0.014 moles × 152.15 g/mol (molar mass of methyl salicylate)
mass of ester = 2.13 g
Therefore, theoretically, you would expect to achieve a mass of 2.13 grams of methyl salicylate when 2 grams of salicylic acid is reacted with excess methanol.