Answer to Question #94057 in General Chemistry for Adisa

Question

What would be the resulting pH if 5ml of 10M HCl were added to 1 litre of pure water?

Answer 1

Solution.

Find the amount of HCl substance in 5 ml with a concentration of 10 M.

$C(HCl) = \frac{n}{V}$

$n = C(HCl) \times V$

n = 0.05 mole

Find the total volume of the solution after mixing 1 liter of water and 5 ml of hydrochloric acid. This is the sum of these volumes.

$V(total) = V(H2O) + V(HCl)$

V(total) = 1.005 liters

Find the concentration of hydrochloric acid in the new solution obtained.

$C'(HCl) = \frac{n}{V(total)}$

C'(HCl) = 0.05 M

Find the pH of the resulting solution. Since hydrochloric acid is a strong acid, we use this formula:

$pH = -lg(C'(HCl))$

pH = 1.30

Answer:

pH = 1.30