To determine the amount of oxalic acid in rhubarb, you chop up and extract 85.2 grams of homogenized rhubarb with hot water. The extract is treated with calcium hydroxide and you isolate 0.6914 grams of solid CaC2O4•H2O.
How many grams of oxalic acid were present in the rhubarb extract?
This is what I had: C2H2O4= 90.04g/mol
85.2g/1•1mol/90.04g= .9462g
mols CaC2O4.H2O = grams/molar mass = 0.6914 g/molar mass CaC2O4.H2O
1 mol CaC2o4.H2O = 1 mol H2C2O4 so multiply mols CaC2O4 x molar mass H2C2O4
To determine the amount of oxalic acid in the rhubarb extract, we need to use the information given about the amount of solid CaC2O4•H2O that was isolated.
The molar mass of CaC2O4•H2O is 146.12 g/mol.
The balanced equation for the reaction between oxalic acid (C2H2O4) and calcium hydroxide (Ca(OH)2) is:
C2H2O4 + Ca(OH)2 → CaC2O4•H2O + 2H2O
From the balanced equation, we can see that the molar ratio between CaC2O4•H2O and C2H2O4 is 1:1. This means that 1 mol of C2H2O4 is equivalent to 1 mol of CaC2O4•H2O.
Using the given information that 0.6914 grams of CaC2O4•H2O was isolated, we can calculate the amount of C2H2O4 present in the rhubarb extract.
0.6914 g CaC2O4•H2O * (1 mol CaC2O4•H2O / 146.12 g CaC2O4•H2O) * (1 mol C2H2O4 / 1 mol CaC2O4•H2O) * (90.04 g C2H2O4 / 1 mol C2H2O4) = 0.448 g C2H2O4
Therefore, there were 0.448 grams of oxalic acid present in the rhubarb extract.