Honors Chemistry Second Semester Review

SI unit for pressure

Pa (pascal)

What do the symbols (g), (s), and (aq) mean in a balanced chemical equation?

gas, solid, liquid

Define Hydrate

ionic compounds that is bonded to water molecules in its crystal lattice

Define Anhydrous Salt

ionic compounds once water has been removed

Hydrate base formula

salt formula * # H20

Define Joule

SI unit of heat and energy

____J = 1 cal

4.184

____cal = 1 Kcal

1000

What is the symbol for heat?

q

Synthesis Reaction base equation

a + b =ab

Decomposition Reaction base equation

ab = a + b

Combustion Reaction base equation

a + O2 = CO2 + H2O

Single Displacement Reaction base equation

ab + c = ac +b

Double Displacement Reaction base equation

ab + cd = ad + cb

Define Mole

SI unit for the amount of something

What is Avogadro’s Number?

6.022 × 10²³

Percent Composition Formula

mass of element/mass of compound x 100

Define Empirical Formula

formula with the smallest whole number ratio of elements in a compound

Define Molecular Formula

formula for the actual number of atoms of each element in a compound

Define Limiting Reagent

substance that limits the extent of the reaction and determines the amount of product

Define Excess Reactant

left over reactants once the reaction stops

Percent Yield Formula

Actual Yield / Theoretical Yield x 100

Define Energy

the ability to do work or create heat

Define Potential Energy

energy stored in an object based on its position or composition

Define Kinetic Energy

energy of motion/movement

Define Stoichiometry

quantitative relationship among the reactants and products in chemical reactions

Define Mole Ratio

ratio between number of moles of any two substances in a chemical equation

Define Mole Ratio

ratio between number of moles of any two substances in a chemical equation

Define 1st Law of Thermodynamics

energy can neither be created nor destroyed only converted from one form to another

Define 2nd Law of Thermodynamics

Entropy always increases in a closed system

Define Entropy

unusable energy that cannot be harnessed to do work, chaos

Define Chemical Potential Energy

energy store in chemical bonds

Define Heat(q)

energy that flows from a warmer to a color object

Define Enthalpy

heat content of a system

Define Endothermic Reaction

reactions where heat is absorbed from the environment

Define Exothermic Reaction

reactions where heat is released into the environment

Define Temperature

measurement of the average kinetic energy of particles at a given moment

Define calorie

amount of energy it takes to raise 1 gram of water 1 degree Celsius

Define Specific Heat

the amount of heat required to raise 1 gram of a substance 1 degree Celsius

What is the Specific Heat formula?

q = cmDeltaT

What is the units for Specific Heat?

grams/degrees Celsius

Define Thermochemistry

the study of heat changes in chemical reactions and phase changes

Define Change in Enthalpy (ΔH)

change in heat content in a chemical reaction or phase change

(ΔH)=

H products - H reactants

+(ΔH)=

endothermic reaction

-(ΔH) =

exothermic reaction

Define Heat of Fusion

solid to liquid (melting) +

Define Heat of Solidification

liquid to solid -

Define Heat of Vaporization

liquid to gas +

Define Heat of Condensation

gas to liquid -

Define (ΔHf°) standard enthalpy of formation

change in heat that results in the formation of 1 mol of substance

What does this equation mean ΔH°rxn = ΣnΔH_f°(products) - ΣmΔH_f°(reactants)

moles x standard enthalpy of formation — moles x standard enthalpy of formation

What are the units for ΔH_f°

kJ/mol