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Question
The metal M reacts vigorously with water to form a solution S and a gas G. The solution S turns red litmus to blue whereas gas G, which is lighter than air, burns with a pop sound. Metal M has a low melting point and it is used as a coolant in nuclear reactors.
(a) What is metal M?
(b) What is solution S? Is it acidic or alkaline?
(c) What is gas G?
(d) Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
(e) Is this reaction exothermic or endothermic?
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Solution
(a) Metal M is sodium (Na), which is used as a coolant in nuclear reactors.
(b) Solution S is sodium hydroxide solution (NaOH). It is alkaline, it turns red litmus to blue.
(c) Gas G is hydrogen gas, which is lighter than air.
(d) 2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g) + HEAT
(e) This reaction is exothermic because it releases excessive heat.
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