Final answer:
The pH of a 1.00 M solution of H3PO4 is 0.
Step-by-step explanation:
To calculate the pH of a 1.00 M solution of H3PO4, we need to consider the dissociation of the acid. H3PO4 is a triprotic acid, meaning it can donate three protons (H+ ions).
The given value of K1 = 7.5 × 10^-3 represents the equilibrium constant for the first dissociation:
H3PO4(aq) ⇌ H+ + H2PO4-
Since the acid is strong, it dissociates completely. Therefore, the concentration of H+ ions from the first dissociation is equal to the initial concentration of H3PO4, which is 1.00 M.
The pH of a solution is defined as the negative logarithm of the concentration of H+ ions:
pH = -log [H+]
Substituting the concentration of H+ ions (1.00 M) into the equation, we get:
pH = -log(1.00) = -0 = 0
Therefore, the pH of a 1.00 M solution of H3PO4 is 0.