Reactions and Energy

• Word equations: Use words to describe a reaction. For example: "hydrogen + oxygen → water"

• Reactants and products: Reactants are the starting materials, and products are the ending materials.

• Exothermic and endothermic: Exothermic reactions release heat, while endothermic reactions absorb heat.

• Investigation: Experiment to determine if a reaction releases or absorbs heat.

• Balanced chemical equations: Use chemical formulas to represent a reaction, ensuring the same number of atoms of each element on both sides.

• Laws: Recall the Law of Conservation of Mass (mass is conserved) and the Law of Constant Proportions (elements combine in fixed ratios).

Acids and Bases

• Acid and base: Acids donate hydrogen ions (H+), while bases accept them.

• Neutralization: Acids and bases react to form a salt and water.

• Investigation: Experiment to observe neutralization reactions.

• Chemical indicators: Substances that change color in acidic or basic solutions.

• Natural indicator: Make a natural indicator from plants or other materials.

• Uses: Identify common uses of acids and bases in everyday life.

• Chemical salt: A compound formed when an acid and a base react.

Chemical Reactions

Types of Reactions

• Precipitation: A solid (precipitate) forms when two solutions are mixed.

• Metal displacement: A more reactive metal replaces a less reactive metal in a compound.

• Neutralization: See above.

• Prediction: Predict if a precipitate will form based on solubility rules.

• Investigations: Experiment to observe precipitation and displacement reactions.

Rates of Reactions

Factors Affecting Rate

• Temperature: Higher temperature increases reaction rate.

• Concentration: Higher concentration of reactants increases reaction rate.

• Surface area: Smaller particles (larger surface area) increase reaction rate.

• Investigations: Experiment to determine how these factors affect reaction rate