To determine which statement is true, let's analyze each one:
1. The salt that forms due to neutralization of phosphoric acid by calcium hydroxide has the formula [tex]\(Ca _4\left( PO _3\right)_2\)[/tex].
- Phosphoric acid is [tex]\(H_3PO_4\)[/tex].
- Calcium hydroxide is [tex]\(Ca(OH)_2\)[/tex].
- In a neutralization reaction, [tex]\(H_3PO_4\)[/tex] reacts with [tex]\(Ca(OH)_2\)[/tex] to form [tex]\(Ca_3(PO_4)_2\)[/tex], not [tex]\(Ca_4(PO_3)_2\)[/tex]. So this statement is false.
2. A Bronsted-Lowry base is a proton donor.
- By definition, a Bronsted-Lowry base is a proton acceptor, not a proton donor. So this statement is false.
3. A conjugate acid-base pair are two substances related to each other by the transfer of a hydroxide.
- In the Bronsted-Lowry theory, a conjugate acid-base pair is related by the transfer of a proton (H⁺), not a hydroxide (OH⁻). So this statement is false.
4. All Bronsted-Lowry acids are water soluble.
- Not all Bronsted-Lowry acids are water soluble. Solubility depends on the specific properties of the compound. So this statement is false.
5. A Bronsted-Lowry base is a proton acceptor.
- This is a correct definition. In the Bronsted-Lowry theory, a base is indeed a proton acceptor. So this statement is true.
Therefore, the correct and true statement is:
A Bronsted-Lowry base is a proton acceptor.
