(1) How many moles of NaOH reacted in Trial 1? (2) What was the experimental mol
ID: 513705 • Letter: #
Question
(1) How many moles of NaOH reacted in Trial 1?
(2) What was the experimental molarity (M) for NaOH in Trial 1?
The NaOH used in this lab was 0.1M
Run 1
0.1388M C6H8O7
ml pH Derivative
0.00 12.96 -0.15
.50 12.90 -0.20
1.0 12.81 -0.43
1.5 12.66 -1.10
2.0 12.31 -2.84
2.5 10.03 -4.81
3.0 6.23 -4.74
3.25 5.87 -2.16
3.50 5.61 -0.97
4.0 5.45 -0.60
4.25 5.20 -0.64
4.50 5.08 -0.55
5.00 4.80 -0.52
5.25 4.69 -0.47
5.50 4.58 -0.44
Explanation / Answer
3 NaOH (aq) + H3C6H5O7 (aq) Na3C6H5O7 (aq) + 3 H2O(l)
H3C6H5O7(aq) + H2O(l) <=> H2C6H7O7- + H3O+ Ka1 = 7.4x10-3
H2C6H5O7- + H2O(l) <=> HC6H6O72- + H3O+ Ka2 = 1.7x10-5
HC6H5O72- + H2O(l) <=> C6H5O73- + H3O+ Ka3 = 4.0x10-7