Types of Chemical Reactions Quiz

Study Notes

Chemical reactions involve the rearrangement of atoms to form new substances.
Reactants are the substances present at the start of a reaction, and products are the substances formed at the end.
Reactions can be represented using chemical equations. For example: A + B → C + D. Where A and B are the reactants, and C and D are the products.

Combination/Synthesis: Two or more reactants combine to form a single product, like: A + B → AB.
Decomposition: A single reactant breaks down into two or more products, like: AB → A + B.
Displacement/Single Replacement: One element displaces another in a compound, like: A + BC → AC + B.
Double Displacement/Metathesis: Two compounds exchange ions to form two new compounds, like: AB + CD → AD + CB.
Acid-Base Reactions: Involve the reaction of an acid and a base to produce a salt and water. This is a specific type of double displacement reaction, illustrated by: acid + base → salt + water.
Combustion: A substance reacts rapidly with oxygen, often producing heat and light. A classic example is a hydrocarbon (like methane) burning in oxygen: hydrocarbon + oxygen → carbon dioxide + water.

Balanced chemical equations show that the number of atoms of each element is the same on both sides of the equation.
This illustrates the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction.
The state symbols (s, l, g, aq) indicate the physical state of substances (solid, liquid, gas, or dissolved in water.)

Magnesium reacting with oxygen illustrates a combination reaction.
The thermal decomposition of calcium carbonate is an example of decomposition.
Iron reacting with copper(II) sulphate solution is a displacement reaction.
Neutralization reactions exemplify acid-base reactions.
Burning propane exemplifies a combustion reaction.

Reactants and products: Identifying these in a chemical equation.
Balancing equations: Ensuring the same number of each atom on both sides of the equation.
State symbols: Using correct symbols for states of matter (s, l, g, aq).

Temperature: Higher temperatures generally increase reaction rates, as molecules move faster and collide more frequently.
Concentration: Higher concentrations of reactants usually lead to faster reactions, as there are more reactant particles in a given space.

Identifying different reactions is important for predicting what substances will be produced.
Factors affecting reaction rates help us understand how to control and optimize chemical processes.
Chemical equations provide a concise way to represent chemical reactions.