Chemistry Final Exam Topics Fall 2024

The variable that is changed or manipulated in an experiment to observe its effect on another variable.

The variable that is measured or observed in an experiment to see how it changes in response to the independent variable.

A substance that cannot be broken down into simpler substances by chemical means; made up of only one type of atom.

A substance made up of two or more different elements chemically bonded together in a fixed ratio.

The physical forms of matter in which atoms or molecules are organized and arranged in different ways.

How close a measurement is to the true or accepted value.

How close repeated measurements are to each other.

The group in an experiment that is not exposed to the independent variable. used as a baseline for comparison.

The smallest repeating unit in an ionic compound, representing the ratio of ions.

Ionic compounds containing two elements, usually a metal and a nonmetal.

Ionic compounds containing three or more elements, including at least one polyatomic ion.

Groups of atoms that carry a charge.

Molecules composed of two atoms of the same element.

The number of protons in an atom's nucleus, which defines the element.

The total number of protons and neutrons in an atom's nucleus.

Subtract the atomic number (number of protons) from the mass number to find the number of neutrons.

Atoms of the same element that have the same number of protons but different numbers of neutrons.

A type of chemical bond formed when a metal atom loses electrons to a nonmetal atom, creating oppositely charged ions that attract each other.

The number of digits in a measurement that are considered reliable and contribute to its precision.

The mass of a substance per unit volume. It tells you how tightly packed the matter is.

A method to determine the volume of an irregularly shaped object by measuring the volume of water it displaces.

The theoretical lowest possible temperature, where all molecular motion stops.

Adding 273.15 to the Celsius temperature to get the equivalent Kelvin temperature.

A method using conversion factors to change units while preserving the value of a measurement.

The average mass of an atom of an element, taking into account the abundance of its isotopes.

A chemical reaction where electrons are transferred between reactants, resulting in a change in oxidation states.

A number assigned to an atom in a molecule or ion that represents its apparent charge, assuming all bonds are ionic, with the electrons belonging to the more electronegative atom.

The reactant that loses electrons and increases its oxidation state. It's the element that gets oxidized.

The reactant that gains electrons and decreases its oxidation state. It's the element that gets reduced.

A reaction where the positive and negative ions of two reactants switch places, forming two new products.

A double replacement reaction where one of the products is an insoluble solid that forms and settles out of solution.

A chemical equation that shows only the ions that participate in the reaction, excluding spectator ions that do not change their state.

Ions that are present in a solution but do not participate in the chemical reaction. They appear on both sides of the complete ionic equation and cancel out.

A measure of concentration that expresses the moles of solute dissolved in 1 liter of solution. It is given by the formula: Molarity = moles of solute / liters of solution.

To convert moles of a substance to liters of a solution, divide the number of moles by the molarity of the solution. This applies to solutions where the molarity is known.

There are several observable indications that a chemical reaction has occurred. These include a change in color, the release or absorption of heat or light, the formation of a precipitate (solid), or the evolution of a gas or odor.

Chemical equations use symbols to represent the states of matter (s = solid, l = liquid, g = gas, aq = aqueous solution), the direction of the reaction (→), reactants and products, and special conditions like heat (∆) or a catalyst (Pt).

The first step in balancing a chemical equation is to write the correct chemical formulas for the reactants and products, forming the skeleton equation. This may require using chemical names to find the formulas if not provided.

Once the skeleton equation is set up, you need to balance the equation by adding coefficients in front of the chemical formulas. The goal is to have the same number of atoms of each element on both sides of the equation. Coefficients represent the number of molecules or moles of each reactant and product.

A synthesis or combination reaction involves two or more reactants combining to form a single product. For example, two elements reacting to form a compound.

Combustion reactions involve burning a substance in the presence of oxygen. This reaction produces heat and light, and the products often include carbon dioxide (CO2) and water (H2O).