室温下，往0.1mol/L的氨水中滴入酚酞试液时，溶液将呈现粉红色。现采取下列措施，滴有酚酞的氨水溶液颜色不会变浅的是
A．往溶液中滴入稀硫酸
B．往溶液中加入NH4Cl晶体
C．把溶液加热至沸腾
D．往溶液中加入NaOH固体
答案：D
题目分析：氨水是弱碱存在电离平衡，即NH3·H2O
OH－＋NH4＋。往溶液中滴入稀硫酸，促进电离，但溶液的碱性降低，颜色变浅。往溶液中加入NH4Cl晶体，抑制氨水的电离，溶液的碱性降低，颜色变浅。把溶液加热至沸腾，氨水分解，氨气溢出，溶液的碱性降低，颜色变浅。往溶液中加入NaOH固体，抑制氨水的电离，但溶液的碱性增强，颜色变深，答案选D。
点评：该题是基础性试题的考查，难度不大。主要是考查学生对氨水电离平衡以及外界条件对氨水电离平衡影响的了解掌握情况，有利于培养学生的逻辑推理能力和发散思维能力。
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