General Chemistry Lecture 3: Chemical Reactions

Flashcards to review key concepts and terminology from the General Chemistry Lecture on Chemical Reactions.

What is a chemical reaction?

A process that converts one substance into another involving breaking and forming of bonds.

What indicates a chemical change?

Evidence of a chemical change includes color change, emission of light, emission/absorption of heat, formation of a solid, and formation of a gas.

What is the Law of Conservation of Mass?

Atoms cannot be created or destroyed in a chemical reaction.

What are reactants in a chemical reaction?

Starting materials that undergo change during the reaction.

What are products in a chemical reaction?

Substances formed as a result of a chemical reaction.

What is required to balance a chemical equation?

The same number of atoms of each element on both sides of the equation.

Give an example of a balanced chemical equation.

CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (l)

What are the types of chemical reactions?

Synthesis, decomposition, single-displacement, double-displacement, precipitation, acid-base, gas evolution, and redox reactions.

What is a precipitation reaction?

A reaction that occurs when two aqueous solutions mix, forming an insoluble solid product.

What occurs during acid-base reactions?

H+ ions from the acid combine with OH- ions from the base to form water.

What is a strong electrolyte?

A substance that completely dissociates into ions in solution.

What is the general equation for a double-displacement reaction?

AB + CD → AD + CB.

What is a redox reaction?

A chemical reaction where there is a transfer of electrons from one reactant to another.

What is the octet rule?

Atoms tend to bond in a way that each atom has 8 electrons in its valence shell.

What is a covalent bond?

A chemical bond that involves the sharing of electrons between two non-metal atoms.

What is the VSEPR theory?

A theory used to predict the shape of molecules based on electron pair repulsion.

Describe a polar covalent bond.

A bond where electrons are unequally shared due to differences in electronegativities.

What determines if a molecule is polar?

The presence of polar bonds and the overall molecular geometry.