Calculate the mass of sucrose that underwent hydrolysis, taking into account the fact that lactic acid weighing 54 g
Calculate the mass of sucrose that underwent hydrolysis, taking into account the fact that lactic acid weighing 54 g was obtained from the formed glucose with a mass fraction of 60% yield
To solve this problem, we need the equations for the hydrolysis of sucrose [1] and the equation for the reaction of lactic acid fermentation of glucose [2].
[1] C12H22O11 + H2O = C6H12O6 (glucose) + C6H12O6 (fructose)
[2] C6H12O6 = 2 CH3-CHOH-COOH
First, we find how much lactic acid would be formed theoretically at 100% yield.
X = 100% * 54g / 60% = 90g.
Now, knowing the total yield of lactic acid after the fermentation reaction, by equation [2] we will find the mass of glucose. Molar mass of glucose = 180.16 g / mol, molar mass of lactic acid = 90.08 g / mol
180.16 g / mol of glucose corresponds to 2 * 90.08 g / mol of lactic acid as
Y g of glucose corresponds to 90 g of lactic acid
Y = (90 * 180.16) / (2 * 90.08) = 90 g.
We found that 90 g of glucose was involved in the fermentation reaction. It is this mass of glucose that is formed as a result of sucrose hydrolysis. Using the equation [1], we find the mass of sucrose. Molar mass of sucrose = 342.3 g / mol
342.3 g / mol of sucrose corresponds to 180.16 g / mol of glucose as
Z g of sucrose corresponds to 90 g of glucose
Z = (90 * 342.3) /180.16 = 171 g.
Answer: 171 g of sucrose