Strong-acid concentration to pH conversion:\nWhat is the pH of an aqueous solution that contains 1 gram of hydrogen ions per litre of solution?

Introduction / Context:
pH is defined as the negative base-10 logarithm of the hydronium (hydrogen ion) molar concentration: pH = −log10[H+]. This problem directly connects mass concentration of hydrogen ions to molarity and then to pH—a frequent quick check in acid–base calculations and titration problems.

Given Data / Assumptions:

• Hydrogen ion mass in 1 L: 1 g H+ per litre.
• Molar mass of H+ ≈ 1 g·mol^−1.
• Strong-acid context with full dissociation and activity ≈ concentration.

Concept / Approach:
Convert grams per litre to moles per litre to find [H+]. Then apply the definition of pH. For high concentrations (≥ 1 M), activity coefficients deviate from unity; however, the textbook convention for such problems uses concentration directly unless stated otherwise.

Step-by-Step Solution:

Verification / Alternative check:
On the pH scale, [H+] = 10^0 M gives pH 0; [H+] = 10^−1 M gives pH 1, etc.

Why Other Options Are Wrong:

• pH 1 corresponds to 0.1 M acid; pH 7 is neutral water; pH 10 is basic.

Common Pitfalls:
Confusing grams per litre with molarity; forgetting the logarithm base 10; considering mole of H2 instead of H+.

Final Answer:
0