Question

Ca=Ca(OH)2=?=Ca(OH)2

Answer 1

Ca + 2H₂O = Ca(OH)₂ + H₂

Ca(OH)₂ + H₂SO₄ = CaSO₄ + 2H₂O

CaSO₄ + Ba(OH)₂ = Ca(OH)₂ + BaSO₄

Answer 2

It seems like you have entered a chemical equation or formula, but it appears to be incomplete. To balance a chemical equation, you need to have both reactants and products on either side of the equation. Additionally, the symbols "=" and "?" are not typical notation in chemical equations.

If you could provide more information or clarify your question, I'd be happy to help you with any chemical equations or concepts you're working on.