Question

Determine the equilibrium pH and speciation (concentration of each species) of the following two solutions. Neglect activity corrections. Species added Total concentration (solution a) HCl 10-3 M (solution b) NaCl 10-3 g.

Answer 1

Answer:

HCl solution - H30+ and Cl ions. pH 3

NaCl - Na+ and Cl-. pH 7

Explanation:

a) HCl solution - the hydrogen ion combines with water molecule to form the hydronium molecule which is responsible for acidity. The chloride ion is also found in solution.

pH = -log [H+] = -log(10^-3) = 3

b) NaCl 10-3 g. The solid dissocates in water forming the Na+ and Cl- ions. None of these ions affect pH