Which of the following pairs lists a substance that can neutralize [tex]Ca(OH)_2[/tex] and the salt that would be produced from the reaction?

A. [tex]HCl[/tex] and [tex]CaCl_2[/tex]

B. HClO and CaHClO

C. [tex]H_2O[/tex] and [tex]Ca(OH)_3[/tex]

D. [tex]H_3PO_4[/tex] and [tex]Ca(PO_3)_2[/tex]



Answer :

To determine which pair lists a substance that can neutralize [tex]\(Ca(OH)_2\)[/tex] and the salt produced from the reaction, we need to understand the chemical reaction between calcium hydroxide and an acid. Calcium hydroxide, [tex]\(Ca(OH)_2\)[/tex], is a strong base. When a strong base neutralizes an acid, the products are usually water and a salt.

Let's analyze each pair given in the options:

1. [tex]\( \mathbf{HCl} \, \text{and} \, CaCl_2 \)[/tex]

- [tex]\(Ca(OH)_2\)[/tex] is a strong base.
- [tex]\(HCl\)[/tex] (hydrochloric acid) is a strong acid.
- The neutralization reaction between [tex]\(Ca(OH)_2\)[/tex] and [tex]\(HCl\)[/tex] can be written as:

[tex]\[ Ca(OH)_2 + 2 HCl \rightarrow CaCl_2 + 2 H_2O \][/tex]

- The salt produced is [tex]\(CaCl_2\)[/tex] (calcium chloride).
- Thus, this pair correctly lists a substance that can neutralize [tex]\(Ca(OH)_2\)[/tex] and the corresponding salt produced.

2. [tex]\(\text{HClO and} \; \text{CaHClO} \)[/tex]

- [tex]\(HClO\)[/tex] (hypochlorous acid) is a weak acid.
- [tex]\(CaHClO\)[/tex] is not a common salt formed by the neutralization of [tex]\(Ca(OH)_2\)[/tex] and [tex]\(HClO\)[/tex].

3. [tex]\( \mathbf{H_2O \; and \; Ca(OH)_3} \)[/tex]

- Water ([tex]\(H_2O\)[/tex]) is not an acid; it is a product of neutralization.
- [tex]\(Ca(OH)_3\)[/tex] does not exist. The correct chemical formula for a possible compound involving calcium and hydroxide ions would be [tex]\(Ca(OH)_2\)[/tex], but that is already our reactant.
- This option is chemically incorrect.

4. [tex]\( \mathbf{H_3PO_4 \; and \; Ca(PO_3)_2} \)[/tex]

- [tex]\(H_3PO_4\)[/tex] (phosphoric acid) can react with [tex]\(Ca(OH)_2\)[/tex], and the reaction can be among many possible forms.
- However, the correct salt produced from [tex]\(Ca(OH)_2\)[/tex] and [tex]\(H_3PO_4\)[/tex] interaction is calcium phosphate, which has the formula [tex]\(Ca_3(PO_4)_2\)[/tex], not [tex]\(Ca(PO_3)_2\)[/tex].
- Therefore, this option lists an incorrect salt.

Given the thorough analysis, the correct pair that lists a substance that can neutralize [tex]\(Ca(OH)_2\)[/tex] and the salt that would be produced from the reaction is:

[tex]\( \boxed{HCl \; and \; CaCl_2} \)[/tex]