Answered

Indicate whether aqueous solutions of each of the following will contain only ions, only molecules, or mostly molecules and a few ions:

a. Acetic acid [tex]$\left( HC _2 H _3 O _2\right)$[/tex], a weak electrolyte
b. NaBr, a strong electrolyte
c. Fructose [tex]$\left( C _6 H _{12} O _6\right)$[/tex], a nonelectrolyte

Write a balanced equation for the dissociation of each of the following strong electrolytes in water:

a. KCl
b. [tex]$CaCl _2$[/tex]
c. [tex]$K _3 PO _4$[/tex]
d. [tex]$Fe \left( NO _3\right)_3$[/tex]



Answer :

GinnyAnswer
Let us analyze each substance to determine whether it forms only ions, only molecules, or mostly molecules with a few ions when dissolved in water.

### Part 1: Electrolytes

#### a. Acetic acid (HC₂H₃O₂)
- Nature: Weak electrolyte.
- Explanation: A weak electrolyte partially dissociates in water, meaning it exists mostly as molecules and produces only a few ions.
- Conclusion: Acetic acid will contain mostly molecules and a few ions.

#### b. Sodium Bromide (NaBr)
- Nature: Strong electrolyte.
- Explanation: A strong electrolyte completely dissociates in water, meaning it exists entirely as ions.
- Conclusion: NaBr will contain only ions.

#### c. Fructose (C₆H₁₂O₆)
- Nature: Nonelectrolyte.
- Explanation: Nonelectrolytes do not dissociate in water and exist solely in molecular form.
- Conclusion: Fructose will contain only molecules.

### Part 2: Dissociation Equations of Strong Electrolytes

For each strong electrolyte, we write the balanced dissociation equation in water.

#### a. Potassium Chloride (KCl)
- Equation:
[tex]\[ \text{KCl (s) } \rightarrow \text{ K}^{+} \text{ (aq) } + \text{ Cl}^{-} \text{ (aq)} \][/tex]

#### b. Calcium Chloride (CaCl₂)
- Equation:
[tex]\[ \text{CaCl}_2 \text{ (s) } \rightarrow \text{Ca}^{2+} \text{ (aq) } + 2\text{Cl}^{-} \text{ (aq)} \][/tex]

#### c. Potassium Phosphate (K₃PO₄)
- Equation:
[tex]\[ \text{K}_3 \text{PO}_4 \text{ (s) } \rightarrow 3\text{ K}^{+} \text{ (aq) } + \text{PO}_4^{3-} \text{ (aq)} \][/tex]

#### d. Ferric Nitrate [Iron(III) Nitrate] Fe(NO₃)₃
- Equation:
[tex]\[ \text{Fe(NO}_3 \text{)}_3 \text{ (s) } \rightarrow \text{Fe}^{3+} \text{ (aq) } + 3\text{NO}_3^{-} \text{ (aq)} \][/tex]

### Summary

1. Acetic acid (HC₂H₃O₂): Mostly molecules and a few ions.
2. NaBr: Only ions.
3. Fructose (C₆H₁₂O₆): Only molecules.

Dissociation equations for strong electrolytes in water:
- KCl: KCl (s) → K⁺ (aq) + Cl⁻ (aq)
- CaCl₂: CaCl₂ (s) → Ca²⁺ (aq) + 2Cl⁻ (aq)
- K₃PO₄: K₃PO₄ (s) → 3K⁺ (aq) + PO₄³⁻ (aq)
- Fe(NO₃)₃: Fe(NO₃)₃ (s) → Fe³⁺ (aq) + 3NO₃⁻ (aq)

This concludes the detailed analysis and balanced dissociation equations for the provided substances.