Certainly! Solubility can be determined by referring to established solubility rules. Let's assess each compound step-by-step:
a. Solubility of Co(NO₃)₂
1. Identify the ions: This compound is composed of cobalt (Co²⁺) and nitrate (NO₃⁻) ions.
2. Apply solubility rules: According to solubility rules, all nitrate (NO₃⁻) salts are soluble in water, regardless of the cation present.
Conclusion: Co(NO₃)₂ is soluble in water.
b. Solubility of Cu₂CrO₄
1. Identify the ions: This compound is composed of copper (Cu²⁺) and chromate (CrO₄²⁻) ions.
2. Apply solubility rules: In general, chromate salts are insoluble in water, except for those containing alkali metals and ammonium (NH₄⁺). Since copper is neither an alkali metal nor ammonium, the chromate rule of insolubility applies.
Conclusion: Cu₂CrO₄ is insoluble in water.
c. Solubility of K₃PO₄
1. Identify the ions: This compound consists of potassium (K⁺) ions and phosphate (PO₄³⁻) ions.
2. Apply solubility rules: Compounds containing alkali metal ions (such as potassium, K⁺) are always soluble in water.
Conclusion: K₃PO₄ is soluble in water.
By following these steps, we determine the solubility of each compound as follows:
- Co(NO₃)₂: Soluble
- Cu₂CrO₄: Insoluble
- K₃PO₄: Soluble
