Question

According to the Arrhenius concept, formation of $O{{H}^{-}}$ (aq) ions in solution is responsible for
(A) Basic substance
(B) Acidic substance
(C) Neutral substance
(D) Slightly acidic substance

Answer 1

Hint: Arrhenius theory explains the concept of acidic and basic nature of compounds when they are added into water basing on the formation of type of ions.

Complete step by step answer:

• Arrhenius theory: This theory was introduced in 1887 by the Swedish scientist Svante Arrhenius. “Acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (${{H}^{+}}$), and that bases ionize in water to yield hydroxide ions ($O{{H}^{-}}$)”.
• Thus basing on the concept of Arrhenius if any substance that forms $O{{H}^{-}}$ ions when they are added into water is called a basic substance.
• So, the correct answer is A.
• The option B is wrong because $O{{H}^{-}}$ is formed by basic substances only not by acidic substances according to Arrhenius.
• Arrhenius is unable to explain the concept of neutral compounds. So, option C is wrong.
  Since the substance produces $O{{H}^{-}}$ it is not a slightly acidic substance according to Arrhenius. So, option D is wrong.

Note: According to Arrhenius,
Acidic substance forms ${{H}^{+}}$, when the substance is added in to water
Basic substance forms $O{{H}^{-}}$, when the substance is added to water.
But according to the Lewis theory of acids and bases, acids are the substance that accepts lone pairs of electrons while bases are the substances that donates lone pairs of electrons. So, don’t confuse between them.