Question

question 5

a strong acid is:

• all of these
• an acid that is very powerful.
• an acid that reacts very vigorously.
• an acid that conducts electricity easily.
• an acid that is very concentrated.

Explanation:

🆕 New Concept Discovered: Acid-Base Strength and Dissociation
How completely an acid breaks apart into ions in water.

Step 1: Define acid strength

In chemistry, the "strength" of an acid is not about how concentrated it is or how dangerous it is. Instead, it refers to how completely the acid molecules break apart (dissociate) into ions when dissolved in water:

$$ \text{HA} ightarrow \text{H}^+ + \text{A}^- $$

A strong acid dissociates completely (\(100\%\)) into hydrogen ions (\(\text{H}^+\)) and anions. A weak acid only partially dissociates, leaving most of its molecules intact.

Step 2: Relate dissociation to electrical conductivity

Because a strong acid dissociates completely, it produces a very high concentration of free-moving ions in the solution.

Since electrical current in a liquid is carried by moving ions, a solution with a high concentration of ions is an excellent conductor of electricity (a strong electrolyte). Therefore, a strong acid is an acid that conducts electricity easily.

Step 3: Eliminate incorrect options

• "an acid that is very concentrated": Concentration refers to how much acid is dissolved in a given volume of water, not how completely it breaks into ions. You can have a dilute solution of a strong acid.
• "an acid that reacts very vigorously": While many strong acids react quickly, reaction rate depends on temperature, concentration, and the specific reactants, not just acid strength.
• "an acid that is very powerful": "Powerful" is a vague, non-scientific term.

Answer:

an acid that conducts electricity easily.