An aqueous solution of an acid conducts electricity. This is because
- A.It contains hydrogen ion
- B.It contains water molecules
- C.Electricity passes through it
- D.It generates electricity
Correct answer
Explanation
The correct answer is A, It contains hydrogen ion. When an acid such as hydrochloric acid dissolves in water, it splits into ions: hydrogen ions (H⁺, which join water molecules as hydronium ions, H₃O⁺) and negative ions such as chloride (Cl⁻). These charged particles are free to move, and their movement through the solution carries the electric current. That is why a bulb in a circuit glows when its electrodes are dipped in dilute acid. Strong acids, which ionise fully, conduct better than weak ones such as acetic acid. Option B is wrong because pure water has very few ions and is a poor conductor; dry hydrogen chloride gas or glucose in water does not conduct either. Option C is wrong because it only repeats the observation without explaining it. Option D is wrong because a solution does not create electricity on its own; it only lets the current pass. Exam tip: acids give H⁺ (H₃O⁺) ions in water, bases give OH⁻ ions; free ions are what let a solution conduct.
Practice Questions
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- A.1,2 and 3
- B.2 and 4
- C.1 and 3 only
- D.1 only
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- A.Joule
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- C.Newton-metre
- D.kg-metre/sec²
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- A.Magnesium
- B.Zinc
- C.Aluminium
- D.Lead
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- A.half of its original value.
- B.double of its original value.
- C.one-fourth of its original value.
- D.four times of its original value.
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- A.Ernest Rutherford
- B.J.J. Thomson
- C.Niels Bohr
- D.Albert Einstein
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