Identification of Cations

Which one of the following metallic ions forms a white

precipitate which remains insoluble in excess aqueous

sodium hydroxide?

• Zn²⁺

• Ca²⁺

• Pb²⁺

When an excess aqueous ammonia is added to a sample solution, no ppt is formed. The sample contains

• Ca²⁺

• Zn²⁺

• Pb²⁺

Which one of the following metallic ions forms a white

ppt which dissolves in an excess of either aqueous

sodium hydroxide or aqueous ammonia to form a colourless solution?

• Zn²⁺

• Pb²⁺

• Ca²⁺

• Cu²⁺

Which one of the following metallic ions form(s) a precipitate which dissolves in an excess of aqueous ammonia?

• Zn²⁺

• Pb²⁺

• Cu²⁺

• Ca²⁺

• Fe²⁺

Which of the following shows the correct ionic equation for the precipitate formed when aqueous NaOH is added to a solution containing Fe³⁺ ions?

• Fe³⁺(aq) + OH^-(aq) → FeOH (s)

• Fe²⁺(aq) + 2OH^-(aq) → Fe(OH)₂ (s)

• Fe³⁺(aq) + OH^-(aq) → Fe(OH)₃ (s)

• Fe³⁺(aq) + 3OH^-(aq) → Fe(OH)₃ (s)

Tags

NGSS.HS-PS1-7

Which of the following shows the correct ionic equation for the precipitate formed when aqueous NH₃ is added to a solution containing Zn²⁺ ions?

• Zn⁺(aq) + OH^-(aq) → ZnOH (s)

• Zn²⁺(aq) + OH^-(aq) → Zn(OH)₂ (s)

• Zn⁺(aq) + 2OH^-(aq) → Zn(OH)₂ (s)

• Zn²⁺(aq) + 2OH^-(aq) → Zn(OH)₂ (s)