Which substance dissolves in water to form a basic solution and also releases carbon dioxide with an acid?
Answer and explanation
Correct answer: Sodium carbonate
The governing concept is the behaviour of salts in water and their reactions with acids. Sodium carbonate dissolves to give a basic solution because carbonate ions hydrolyse water and produce hydroxide ions. With an acid, it releases carbon dioxide: Na2CO3 + 2HCl → 2NaCl + H2O + CO2. Thus option A satisfies both conditions. Sodium hydroxide is basic but does not release CO2 with acid, while sodium chloride and copper sulphate do not meet both requirements.
Frequently asked questions
What is the correct answer to this question?
Sodium carbonate
Why is this the correct answer?
The governing concept is the behaviour of salts in water and their reactions with acids. Sodium carbonate dissolves to give a basic solution because carbonate ions hydrolyse water and produce hydroxide ions. With an acid, it releases carbon dioxide: Na2CO3 + 2HCl → 2NaCl + H2O + CO2. Thus option A satisfies both conditions. Sodium hydroxide is basic but does not release CO2 with acid, while sodium chloride and copper sulphate do not meet both requirements.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
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