Question

Calculate the pH of the following solutions:
a) Calculate the pH of the solution obtained by mixing 20.00 mL of 1.00 M HCl with water until
a volume of 2000 mL.
b) Calculate the pH by mixing 5.00 mmol of HNO3 with 5.00 mmol of KOH, in a total volume of
1000 mL of solution
c) Calculate the pH by mixing 5.00 mmol of C6H5COOH with 3.00 mmol NaOH, and bring up to
volume 300 mL.
d) Calculate the pH by dissolving 0.611 g of C6H5COOH in 300 mL of a 0.01000M NaOH solution.
e) Calculate the pH of the solution obtained by mixing 25.00 mL of 0.1000 M NaOH with 25.00
mL of HClO 0.1000 M.
f) Calculate the pH of the solution obtained by mixing 25.00 mL of 0.1000 M HCl with 25.00
mL of NaOCl 0.1000 M.

Answer 1

Mole of Hel = 0.020 L xl.co mole/L = 0.020 mote! [hei] = 0.020 mole = 1x 105 m. 2000 L pH = -log [H +] = -log (1x 105) = 5.0 pH-5.0 Ans . HNO3 is strong and and rot is Strong base, So all the Haloz is neutralized by KoH. Solution is neutral, pH = 7.0 pra fothy cooH) = 4.20 Mole of salt (&ts coona) = 3.00 mmole o Mole of C 6 Hs CooH = (5.00-3.W) = 2.00 mmole. a Bay] Acid] pH = 4.20 + lig ( 30 ) PH = 4.376 300 ml of Mole of 0.01000 m NaOH = 0.300 L x 0.01000 mole/L - 0.003 mole Gts CooH = Oifllg Leon /122-12 gf more atmore - - o 0.005 mole salt = 0.003 mole and mole on acid (0.005- 0.003) Mole of 0002 mole PH2 pka + log Balt] [Acid pH=9. 20 IPH = 4.376 0.003 0.002