A25.0mL sample of 0.1MNH3 is titrated with 0.1M HCl.

Question

A . calculate the pH value of the solution
after the following volume of 0.1M
HCl are added. 0.00 mL,5.00
mL,10.00 mL,15.00 mL,20.00
mL,22.00 mL,24.00
mL,25.00 mL and 26.00 mL
B. draw a table and put the pH value
corresponding to each value in ttable
C. Draw the titration curve
D. Name the appropriate indicator for this titration.

Answer 1

A. 0.00 mL: pH = 11.00
5.00 mL: pH = 9.00
10.00 mL: pH = 7.00
15.00 mL: pH = 5.00
20.00 mL: pH = 4.00
22.00 mL: pH = 3.50
24.00 mL: pH = 3.00
25.00 mL: pH = 2.50
26.00 mL: pH = 2.00

B. Volume of HCl (mL) | pH
0.00 | 11.00
5.00 | 9.00
10.00 | 7.00
15.00 | 5.00
20.00 | 4.00
22.00 | 3.50
24.00 | 3.00
25.00 | 2.50
26.00 | 2.00

C. The titration curve would look like a bell-shaped curve, with the pH increasing from 11.00 to 2.00 as the volume of HCl increases.

D. The appropriate indicator for this titration is phenolphthalein.