chemistry 🧪 (Mendeleev and electrolysis half equations)

Why was mendeleevs table more widely accepted than others?

Because he left gaps in the (periodic) table for Undiscovered elements

He predicted the properties of these undiscovered elements

When these elements were later discovered, their properties matched Mendeleev’s predictions

He changed the atomic weight order of the elements.

What’s the half equation for the hydroxide ions (OH-) at the anode?

4OH —>O2 + 2H2O + 4e-

What’s the reduction half equation for hydrogen ions at the cathode?

2H+ + 2e- —> H2

In aqueous electrolysis, when is hydrogen gas produced at the cathode?

• When the metal in the solution is more reactive than hydrogen (e.g., sodium, potassium).

Which common metals are less reactive than hydrogen and will form at the cathode instead?

Copper, silver, and gold

In aqueous electrolysis, when is oxygen gas produced at the anode?

When there are no halide ions (chloride, bromide, iodide) present in the solution.