Which description is true of 0.02 M Ca (OH) 2 if Ca (OH) 2 completely dissociates in water? A. It's a dilute strong acid. B. It's a dilute strong base. C. It's a dilute weak base. D. It's a concentrated weak base. E. It's a concentrated weak acid.

Question

Chemistry

Baird

10 March, 00:15

Which description is true of 0.02 M Ca (OH) 2 if Ca (OH) 2 completely dissociates in water? A. It's a dilute strong acid. B. It's a dilute strong base. C. It's a dilute weak base. D. It's a concentrated weak base. E. It's a concentrated weak acid.

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Answers (1)

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Theodore Galloway · Answer 1

Answer: B. It's a dilute strong base.

Explanation:

1) Definition of acids and bases: as per Bronsted-Lowry model, an acid is a substance that donates hydrogen ions and a base is a substance that accepts hydrogen ions.

Ca (OH) ₂ does not have hydrogen ions to donate, but it can accept hydrogen ions to form H₂O according to this equation: H⁺ + OH⁻ → H₂O.

Hence, Ca (OH) ₂ is a base.

2) Definition of strong base: a strong base is a base that dissociates completely into metallic and hydroxide ions in aqueous solutions, while a weak base dissociates partially.

Hence, Ca (OH) ₂ is a strong base.

3) Definition of dilute: it refers to a solution meaning that the substance is not pure and the concentration is low. Since, the solution the Ca (OH) ₂ is 0.02 M means that it is dilute.

Therefore, we have found that the description of 0.02 M Ca (OH) ₂ is that is is a dilute strong base (option B).