Final answer:
Concrete curing is a process called hydration, where water causes the chemical reaction of cement hardening. Mixing concrete ensures it remains workable before curing, and while mixing generally speeds up chemical reactions, in this case, it's for homogeneity. Other factors like temperature and moisture have greater effects on curing speed.
Step-by-step explanation:
The process of concrete curing is indeed a chemical reaction, and it is called hydration. When concrete is mixed, the ingredients initiate this curing process, which involves the hydration of cement to form a hard matrix that binds the aggregate together. This reaction is exothermic and occurs over time, thereby hardening the concrete. While it is true that mixing tends to increase the rate of most chemical reactions, in the case of concrete, mixing is done to ensure that the concrete mix is homogeneous and workable before it starts curing. Continuous mixing does not slow down the curing process; instead, it prevents the concrete from setting too quickly and allows for proper placement and forming. Other factors such as temperature and moisture content can have a more significant impact on the rate at which concrete cures.
There are other examples where the rate of reactions is intentionally slowed down, such as in the addition of stabilizers to prevent the premature polymerization of plastic materials, or the use of inhibitors in food to prevent oxidation and spoilage. Chemists often control reaction rates by varying the temperature, concentration, or by the addition of a catalyst or inhibitor.