Using Everyday Equations Every minute of the day chemical reactions are taking place both in and around you. What makes something a chemical reaction? A chemical reaction involves one or more substances, the reactants, changing into one or more substances, the products. Reactants Products “ ” means “yields” or “reacts to produce.”
Chemical reactions can be described many ways. One is by using a word equation. A word equation is an equation where reactants and products are represented by words. Example: methane + oxygen Word equations, while useful, are cumbersome. To better describe a reaction, writing the formulas is used. A chemical equation uses formulas of reactants (on the left) separated by an arrow from products (on the right). carbon dioxide + water
Example: Fe + O 2 (Skeleton equation) - does not indicate the relative amounts of reactants and products Most often symbols are used to describe the state (i.e., gas, solid, etc.) of each substance Fe 2 O 3
H is the only nonmetal listed. H 2 may be displaced from acids or can be given off when a metal reacts with H 2 O (producing H 2 + metal hydroxide). The reaction with H 2 O depends on metal reactivity & water temp.
Q: will Mg react with H 2 O?
cold H 2 O hot H 2 O steam acid NR A: No for cold, yes if it is hot/steam Mg + H 2 O H 2 + ZnCl 2 Complete these reactions: Al + H 2 O(steam) Cu + H 2 O Ca + H 2 SO 4 Na + H 2 O H 2 + Mg(OH) 2 H 2 + Al(OH) 3 H 2 + CaSO 4 H 2 + NaOH Q: Zn + HCl Cu Hg Ag Ca Mg Al Zn Fe Ni Sn Pb H Au Li Na K