Write an equilibrium expression for each chemical equation involving one or more solid or liquid reac- tants or products. CO2−3(aq)+H2O(l)⇌HCO−3(aq)+OH−(aq) Use A for [CO2−3], B for [H2O], C for [HCO−3], D for [OH−] Can someone help?

Here are the rules for writing equilibrium expressions:

1) It's formatted so that it's the concentration of the products over the concentration of the reactants. Any coefficients of substances are written as the exponents of the concentration of that substance. 2) If a reaction contains only one liquid, do not include it in the expression. However, if multiple liquids are present, then you include all of them in the expression. So a reaction where water is the only liquid would not contain water in its equilibrium expression.

3) Solids are never included in the equilibrium expression.

This is the reaction you were given: ##CO_2^"-3"##(aq) + ##H_2O##(l) ⇌ ##HCO_3^-##(aq) + ##OH^-##(aq)

Looking at this, you can see that water is the only liquid present, therefore you do not include it in the equilibrium constant. So, according to the formatting rules I mentioned above, here's what the equilibrium expression would look like: You don't have to include the states in the expression because the brackets implies concentration, which is typically in mol/L.