Question

Balance Cr(OH)3 + Br2 = CrO4 2- + Br-

Answer 1

The question involves balancing a redox chemical equation for Cr(OH)3 and Br2 to form CrO4 2- and Br-. The steps include balancing chromium and bromine half-reactions, then combining them and simplifying.

Step-by-step explanation:

The balance of the chemical equation Cr(OH)3 + Br2 = CrO4 2- + Br- involves a redox reaction where chromium and bromine change their oxidation states. In acidic solution, the Cr3+ is oxidized to CrO42- and Br2 is reduced to Br-.

First, let's balance the half-reaction involving chromium:

1. Cr3+ is oxidized to CrO42-. Four water molecules provide the additional oxygen atoms needed, resulting in 4H2O + Cr3+ becoming CrO42- + 8H+ + 3e-.
2. The hydroxide ions (OH-) can be added to both sides to balance the charge in a basic solution.

Next, let's consider the half-reaction involving bromine:

1. Br2 is reduced to 2 Br-, where 2 electrons are needed, so Br2 + 2e- = 2 Br-.

Now, both half-reactions can be combined, ensuring that the number of electrons lost in the oxidation half-reaction is equal to the electrons gained in the reduction half-reaction. Once combined, the final step is to simplify.