Chemical Reactions & Equations

What are the five main types of chemical reactions?

• addition, substitution, reduction, oxidation, polymerization

• synthesis, decomposition, single displacement, double displacement, combustion

How do you balance a chemical equation?

• Change the chemical elements involved

• Ignore the number of atoms on each side

• Add random numbers to the equation

• Adjust the coefficients of the reactants and products to ensure the number of atoms for each element is the same on both sides of the equation.

Explain the concept of chemical reaction rates.

• Chemical reaction rates are only applicable to solid-state reactions.

• Chemical reaction rates describe how quickly reactants are transformed into products.

• Chemical reaction rates are constant and do not change over time.

• Chemical reaction rates are solely dependent on the temperature of the reaction.

Differentiate between endothermic and exothermic reactions.

• Exothermic reactions absorb heat

• Endothermic reactions absorb heat, while exothermic reactions release heat.

• Endothermic reactions release heat

• Endothermic reactions are faster than exothermic reactions

What are redox reactions and how are they identified?

• Redox reactions involve light absorption

• Redox reactions are identified by changes in color

• Redox reactions involve electron transfer and are identified by changes in oxidation states.

• Redox reactions involve only protons transfer

Define synthesis reaction and provide an example.

• An example of a synthesis reaction is the combustion of methane to form carbon dioxide and water.

• A synthesis reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex product. An example is the combination of iron and sulfur to form iron(II) sulfide: Fe + S -> FeS.

• Synthesis reactions only involve one reactant combining with another to form a product.

• A synthesis reaction is a type of chemical reaction that involves the breakdown of a complex substance into simpler products.

What is a decomposition reaction? Give an example.

• An example of a decomposition reaction is the formation of water from hydrogen and oxygen.

• A decomposition reaction is a type of chemical reaction where a compound breaks down into a single substance.

• A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. An example of a decomposition reaction is the breakdown of hydrogen peroxide into water and oxygen gas.

• A decomposition reaction is a type of chemical reaction where a compound combines with oxygen.

Explain the process of balancing a redox reaction.

• Balancing hydrogen atoms by adding OH- ions

• The process of balancing a redox reaction involves assigning oxidation numbers, splitting the equation into half-reactions, balancing atoms other than hydrogen and oxygen, balancing oxygen atoms by adding water molecules, balancing hydrogen atoms by adding H+ ions, balancing charge by adding electrons, and finally balancing the number of electrons in both half-reactions.

• Balancing atoms by adding more unbalanced elements

• Balancing charge by removing electrons

What factors can affect the rate of a chemical reaction?

• Temperature, concentration of reactants, surface area, presence of a catalyst, pressure

• Humidity level

• Color of the reactants

• Time of day

Describe the difference between a reversible and irreversible reaction.

• Reversible reactions always result in a net loss of energy

• Irreversible reactions can be easily reversed

• The main difference between a reversible and irreversible reaction is the ability to proceed in both directions for reversible reactions, whereas irreversible reactions can only proceed in one direction.

• Reversible reactions only occur in living organisms