To determine the formula for phosphorous acid, we need to understand the relationship between phosphorous acid and its corresponding anion. Here’s the step-by-step process:
1. Identify the Relevant Anions:
- Phosphate: [tex]\( PO_4^{3-} \)[/tex]
- Phosphite: [tex]\( PO_3^{3-} \)[/tex]
2. Determine the Relevant Anionic Form for Phosphorous Acid:
- Phosphorous acid typically relates to the phosphite ion.
3. Construct the Acid Formula:
- Phosphorous acid will have the formula corresponding to the phosphite ion [tex]\( PO_3^{3-} \)[/tex].
- Since the phosphite ion has a charge of [tex]\(-3\)[/tex], to balance this charge, it requires three hydrogen ions [tex]\( H^+ \)[/tex].
4. Combine the Hydrogen Ions with the Phosphite Ion:
- Adding three hydrogen ions [tex]\( H^+ \)[/tex] to phosphite [tex]\( PO_3^{3-} \)[/tex] forms the phosphorous acid [tex]\( H_3PO_3 \)[/tex].
Thus, the formula for phosphorous acid is [tex]\( H_3PO_3 \)[/tex].
Therefore, the correct answer is:
[tex]\[ H_3PO_3 \][/tex]
