pH scale is used to determine how acidic, neutral or basic a solution is.
pH can be calculated using the following equation
pH = -log[H⁺]
HNO₃ is a strong acid therefore completely dissociates into its ions as follows
HNO₃ --> H⁺ + NO₃⁻
1 mol of HNO₃ dissociates to produce 1 mol of H⁺ ions
Therefore [HNO₃] = [H⁺]
[H⁺] = 0.150 M
since concentration has been given, its not necessary to consider the volume as concentration is constant throughout the whole solution
pH = -log(0.150 M)
pH = 0.82
the pH of solution is 0.82