1. Place about 3ml of 0.1 M chromium III chloride solution into a test tube and record the color. Add drops of 2M sodium hydroxide until a precipitate of Cr(OH)3 first forms.

Question

2. Add more drops of sodium hydroxide until the precipitate dissolves to form the complex ion [Cr(OH)4]^-.
Write an equation for this reaction

Answer 1

1. CrCl3(aq) + 3NaOH(aq) → Cr(OH)3(s) + 3NaCl(aq)
2. Cr(OH)3(s) + NaOH(aq) → [Cr(OH)4]^-(aq)

Answer 2

Write the complete equation

Answer 3

1. CrCl3(aq) + 3NaOH(aq) → Cr(OH)3(s) + 3NaCl(aq)
2. Cr(OH)3(s) + NaOH(aq) → Na[Cr(OH)4](aq)