How do you know when the reaction between baking soda and an acid ingredient has ended

Can someone me with 1 to 4 plz. fast

An observation that requires measurement is called quantitative observable or qualitative

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?