Ammonium phosphate and nickel(II) nitrate solutions are mixed, what precipitates out?
Ni₃(PO₄)₂
Ni3(PO4)2is insoluble in water solution.
To determine what precipitates out when ammonium phosphate and nickel(II) nitrate solutions are mixed, we need to identify the possible precipitates by examining the solubility of the resulting compounds formed.
Ammonium phosphate has the chemical formula (NH₄)₃PO₄, and nickel(II) nitrate has the chemical formula Ni(NO₃)₂.
First, let's write the balanced chemical equation for the reaction:
(NH₄)₃PO₄ + Ni(NO₃)₂ → ?
Next, let's check the solubility of the possible compounds formed by referring to solubility rules:
1. Most nitrates (NO₃⁻) are soluble.
2. Ammonium compounds (NH₄⁺) are generally soluble.
3. Phosphates (PO₄³⁻) are usually insoluble, except for those of group 1 cations and ammonium.
Based on these solubility rules, we can conclude that nickel phosphate (Ni₃(PO₄)₂) will be formed as a precipitate.
So, when ammonium phosphate and nickel(II) nitrate solutions are mixed, nickel phosphate (Ni₃(PO₄)₂) will precipitate out.
To determine if a precipitate forms when ammonium phosphate and nickel(II) nitrate solutions are mixed, we must first examine the possible ionic reactions that can occur.
Ammonium phosphate (NH4)3PO4, when dissolved in water, dissociates into ammonium ions (NH4+) and phosphate ions (PO4^3-):
(NH4)3PO4(s) → 3NH4+(aq) + PO4^3-(aq)
Nickel(II) nitrate, Ni(NO3)2, when dissolved in water, dissociates into nickel(II) ions (Ni^2+) and nitrate ions (NO3^-):
Ni(NO3)2(s) → Ni^2+(aq) + 2NO3^-(aq)
When the two solutions are mixed, the following possible reactions can occur based on the potential combination of ions:
1. Ammonium ions react with nitrate ions:
NH4+(aq) + NO3^-(aq) → NH4NO3(aq)
2. Nickel(II) ions react with phosphate ions:
Ni^2+(aq) + PO4^3-(aq) → Ni3(PO4)2(s)
Analyzing these potential reactions, we can see that nickel(II) ions (Ni^2+) react with phosphate ions (PO4^3-) to form a precipitate called nickel(II) phosphate (Ni3(PO4)2). Therefore, when ammonium phosphate and nickel(II) nitrate solutions are mixed, nickel(II) phosphate will precipitate out.
If you want to verify this result experimentally, you can mix the two solutions in a test tube and observe if a solid precipitate forms. Additionally, you can obtain the solubility product constant (Ksp) values for nickel(II) phosphate to confirm its insolubility.