Chemical Reactions and Equations

(a) The process of corrosion involves the oxidation of refined metal by atmospheric oxygen to produce a more stable product, such as oxides. Throughout the corrosion process, the metal gradually deteriorates. Iron rusting is a prime example of corrosion since it results in the formation of iron oxide. Annually, millions of dollars are paid to …

Explain the following terms with one example each.
(a) Corrosion
(b) Rancidity Read More »

Flushing nitrogen into food packets that include oil and fat-containing substances is mainly done to stop rancidity, which occurs when oil or fat combines with air and produces an undesirable smell and flavour. Therefore, rancidity is avoided by eliminating nitrogen, which creates an environment that is not reactive.

Iron articles are painted to prevent them from rusting. When a metal surface is unpainted, it comes into touch with atmospheric oxygen and develops Iron(III) oxide when there is moisture present. However, if the surface is painted, it is protected from moisture and the elements, preventing rusting.

Copper metal is the shining brown element (Cu). The metal reacts with atmospheric oxygen when heated in air to produce copper oxide. Thus, the substance that is black in colour is copper oxide. 2Cu(s) + O2(g) → 2CuO(s)

(a) The element being oxidised is the one to which oxygen is added in a chemical reaction to form the element\’s corresponding oxide. Example: O2(g) + 4K(s) = 2K2O (s) O2 (g) + H2S = O2 + SO2 (b) A compound is said to be reduced in a chemical reaction when the oxygen is removed …

Explain the following in terms of the gain of oxygen with two examples each.
(a) Oxidation
(b) Reduction Read More »

In a double displacement reaction, the ions are exchanged between the compounds when two solutions containing soluble salts are combined. One of these compounds settles to the bottom of the container when it has solid formed and is insoluble in water. This substance is known to as a precipitate, and the associated reaction is known as …

What do you mean by a precipitation reaction? Explain by giving examples. Read More »

Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) + 2Ag(s)

A displacement reaction occurs when a more reactive substance takes a less reactive one out of its salt solution; a double displacement reaction occurs when two compounds exchange ions. In a displacement reaction, only a single displacement takes place, whereas, in a double displacement reaction, two displacement takes place between the molecules. e.g. Single displacement …

What is the difference between displacement and double displacement reactions? Write relevant equations for the above. Read More »

(a) Thermal decomposition reaction (Thermolysis ) Potassium chlorate decomposition: Potassium chlorate breaks down into potassium chloride and oxygen when heated strongly. The production of oxygen is produced through this reaction. 2KClO3 + Heat → 2KCl + 3O2 (b) Electrolytic decomposition reaction (Electrolysis) Sodium chloride decomposes into sodium and chlorine when electricity is applied to molten …

Write one equation each for decomposition reactions in which energy is supplied in the form of heat, light or electricity. Read More »

The decomposition reaction is defined as the splitting of bigger molecules into two or smaller molecules, whereas the combination reaction is considered to be the reaction of two or more molecules to generate a larger molecule. Essentially, this describes how the decomposition process is the combination reaction\’s polar opposite. Since the heat from the surrounding …

Why are decomposition reactions called the opposite of Combination reactions? Write equations for decomposition reactions. Read More »