Chem 13 and 14 vocab for final

Heat

The transfer of energy from a warmer place to a colder place

Kilocalories (Kcal)

1000 calories, also known as Nutritional or big “C” Calorie

Joule

SI unit for energy/heat a 1cal=4.184 J. Must use this unit for heat equation

“m”

(grams). Symbol that represents the amount of “MASS” in the heat equation

Specific heat

(j/g^degree C). Amount of energy required to raise 1 g of ANY substance in 1 degree C

“ENDO”thermic

Rezction where energy (heat) is required. The environment feels colder (ICE PACK)

Calorimeter

Insulated device, water measures heat gain’oss when substance burns

positive enthalpy (H+)

Heat is gained during a chem reaction (ENDO). Products higher than reactants

energy

ability to do work or produce heat

“c” (from heat equation)

(j/g^degree c). Symbol that represents the “specific heat” in the heat equation

Calculating the heat equation

“q”=”m”x”c”x”T”

q=mcat

Q=j

m=g

c=j/g^degree c)

Kj (Kilojoule)

1000 joules

“c”alorie (small “c”)

amount of energy needed to raise ine g of WATER 1 degree celsius

(ΔT) (from heat equation)

symbol that represents “change in Temp” in the heat equation

Chemical potential energy

Energy that is locked in the bonds of chemical substances (food, gas, etc).

“EXO”thermic

Reaction where energy (heat) is given off. Environment feels warmer (Hand warmers)

water

substance with a very high specific heat. Absorbs heat without quick rise in Temp.

negative enthalpy (H-)

Heat is LOST during a chemical reaction (EXO). Reactants higher than products

“q”

(J) symbol for the amount of heat gained or lost in the heat equation

Law of Conervation of Energy

States that energy can neither be created nor destroyed but it can be transformed EX: mechanical in electrical , solar into electrical

Endothermic

Postive Enthaply, H+, heat gained, products higher than reactants, environment feels colder, cold pack

Exothermic

Negative enthalpy, H-, heat lost, reactants higher than products, enviroment feels warm, hand warmer

Endothermic graph

Exothermic graph

Catalyst

A substance that increases the rate of a reaction, but does not get "used" during the reaction is known as a

Acitvated Complex

A temporary unstable arrangement of atoms in which old bonds are breaking and new bonds are forming is called a/an

A catalyst _____ the activation energy required for a reaction to take place

decreases

An inhibitor ____ the activation energy required for a reaction to take place

Increases

What increases the rate of reaction

decreasing the activation energy, adding a catalyst, increaing the concentration of the reactants, increasing the temperature

The rate of reaction depends on

colliosn energy, collison frequency, and collison orientation

As the temperature of a reaction is increased, the rate of the reaction increases because the __________.

reactant molecules collide more frequently and with greater energy per collision

A catalyst can increase the rate of a reaction __________.

by providing an alternative pathway with a lower activation energy

A burning splint will burn more vigorously in pure oxygen than in air because

oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air.