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Question
An element E reacts with water to form a solution which turns phenolphthalein solution pink. The element E is most likely to be ______.
Options
S
Ca
C
Ag
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Solution
An element E reacts with water to form a solution which turns phenolphthalein solution pink. The element E is most likely to be Ca.
Explanation:
Phenolphthalein is a pH indicator that turns pink in basic (alkaline) solutions. Calcium (Ca) reacts with water to form calcium hydroxide [Ca(OH)2], which is a strong base. In contrast, sulphur (S) and carbon (C) are non-metals that do not form basic solutions, while silver (Ag) is unreactive and does not react with water.
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