Chemistry Vocab 5th Six weeks

Absolute zero

The temperature given a value of zero on the Kelvin temperature scale.

Activated complex

Transitional structure that results from an effective collision of reactants

Activation energy

The minimum energy required to transform reactants to activated complex

Atmosphere of pressure

Equivalent exactly to 760 mm of Hg or torr

Boyles law

Volume of a fixed mass of gas varies inversely with the pressure at constant temperature

Calorimeter

A device used to measure the heat absorbed or released in a chemical or physical change

Charles Law

Volume of a fixed mass of gas at constant pressure varies directly with the Kelvin temperature

Combined Gas law

The relationship between pressure, volume, and temperature of a fixed amount of gas

Dalton's Law

The total pressure of a mixture of gases is equal to the sum of partial pressures of component gases

Diffusion

Spontaneous mixing of the particles of two substances caused by random motion

Effusion

Process by which gas particles pass through an opening due to random motion

Endothermic reaction

reaction which the energy of reactants is lower than that of the products at the reaction's completion

Enthalpy change

The amount of energy absorbed or lost by a system during a process at constant pressure.

Exothermic reaction

reaction which the energy of reactants is higher than that of the products at the reaction's completion

Gay Lussac's law

The pressure of a fixed mass of gas at constant volume varies directly with the Kelvin temperature

Heat

Energy transferred between samples of matter because of a difference in temperature.

Heat of reaction

Quantity of energy released or absorbed as heat during a chemical reaction

Ideal gas law

The mathematical relationship of pressure, volume, temperature, and the number of moles of a gas.

Joule

The SI or metric unit of heat energy

Kinetic molecular theory

A theory based upon the idea that particles of matter are always in motion

Law of conservation of energy

Also called the first law of thermodynamics stating energy is neither created nor destroyed it is conserved

Limiting reactant

The reactant controlling the amount of product that can form in a chemical reaction

Pressure

Force per unit area on a surface

Specific heat

Amount of energy required to raise the temperature of 1g of water 1˚ in temperature

STP

Equals zero degrees Celsius and one atmosphere of pressure

Temperature

Measure of the average kinetic energy of particles in a sample of matter

Theoretical yield

Maximum amount of product that can be made from a given amount of reactant

Ideal gas constant

Designated by the letter R it has the value of 0.0821 L ∙atm/mol ∙K

Excessive Reactant

The reactant that is not completely consumed in a chemical reaction