How many litres of water must be added to litre of an aqueous solution...
Given:
pH of HCl solution = 1
pH of final solution = 2
To find:
Amount of water to be added to the HCl solution
Solution:
Step 1: Calculate the concentration of H+ ions in the HCl solution
The pH of a solution is defined as the negative logarithm (base 10) of the concentration of H+ ions in the solution.
pH = -log[H+]
1 = -log[H+]
[H+] = 10^-1 = 0.1 M
Step 2: Calculate the concentration of H+ ions in the final solution
pH = -log[H+]
2 = -log[H+]
[H+] = 10^-2 = 0.01 M
Step 3: Calculate the difference in concentration of H+ ions between the two solutions
Change in [H+] = [H+]final - [H+]initial
Change in [H+] = 0.01 M - 0.1 M = -0.09 M
Step 4: Calculate the volume of water to be added to the HCl solution
As the concentration of H+ ions decreases by 0.09 M, the same amount of water should be added to the solution.
Volume of water = Change in [H+] / [H+] in water = 0.09 M / 0.1 M = 0.9 L
Therefore, 0.9 liters of water must be added to 1 liter of the HCl solution to create an aqueous solution with a pH of 2.
Answer: Option (d) 0.9 L