常温下，将0.01 mol的HCl气体溶于水配成1 L溶液，该溶液的pH为多少？
Show the answer and explanation
Correct answer
B. 2
Principle or equation
pH = -lg c(H+)。HCl是强电解质，完全电离，溶液中c(H+)等于HCl的浓度。
Why this answer is correct
HCl的物质的量为0.01 mol，溶液体积为1 L，所以c(HCl) = 0.01 mol/L。由于完全电离，c(H+) = 0.01 mol/L = 10^-2 mol/L，因此pH = -lg(10^-2) = 2。
Example
若0.001 mol HCl溶于水配成1 L溶液，则c(H+) = 10^-3 mol/L，pH = 3。
This published item includes a stored explanation and passed the platform’s publication workflow. It is independent preparation material, not a claim of an official or recalled examination question.