For an experiment, calorimetry and titrations were done on 5 unknown chemicals,

For the calorimeter part, 40 mL of water was added to a beaker and the experimental data when the substances were added was:

Sample	Mass (g)	T initial (C)	T Final (C)	Delta T (C)
a	4.02	20.6	19.6	-1.0
b	3.99	20.6	19.0	-1.6
c	4.00	20.6	18.0	-2.6
d	4.02	20.8	28.0	+7.2
e	4.01	20.6	20.4	-0.2

1) With this, calculate the Delta H of each solution and the concentration of each in molarity.

D was found to be KOH and was used to titrate samples a and b to figure out which one was vitamin C and which one was citric acid. With the 40 mL KOH solution, 25 mL was transferred into a beaker with 100 mL of distilled water to make a 125 mL diluted solution of KOH to titrate the samples. The following data was found:

Titration # and sample (a or b)	Change in volume (mL)
Sample a titration 1	20.90
sample a titration 2	20.96
sample b titration 1	9.00
sample b titration 2	8.96

2) Find the concentration of the acid, molar mass of acid and which acid each titration is referring to. Use the back titration technique to find the values.