单项选择题 When 500mL of 0.10mol·L-1 NaOH is reacted with 500ml of 0.20mol·L-1 HCl the final concentration of H+ is（）
单项选择题 A certain weak acid is 10% dissociated in 1.0mol·L-1 solution.In 0.10mol·L-1 solution，the percentage of dissociation would be（）。
单项选择题 Which one of the following ions would give a basic solution upon addition to water？（）