How could you safely determine if a base is stronger than an acid?

Since tasting or touching the texture or surface could be deemed unsafe. It would be best to use a pH meter or litmus paper. pH meter will accurately determine pH. Litmus paper if red will be acidic and basic if blue. You can also perform conductivity test. Else, you can also perform hydrogen test.

The answer to this problem is. 67

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -