H Chemistry: Unit 6

Question 1

stoichiometry

Answer 1

quantitative relationship amongst reactants and products in a balanced chemical equation

Question 2

limiting reagent

Answer 2

reactant that determines the amount of product made(theoretical yield)

Question 3

excess reactant

Answer 3

reactant that will be left over after the reaction has gone to completion

Question 4

percent yield

Answer 4

actual yield/theoretical yield x 100

Question 5

energy

Answer 5

E; ability to do work or produce heat

Question 6

2 basic forms of energy

Answer 6

potential energy & kinetic energy

Question 7

potential energy

Answer 7

energy stored in an object based in its position or chemical composition

Question 8

kinetic energy

Answer 8

energy of motion

Question 9

1st Law of Thermodynamics

Answer 9

states that energy cannot be created nor destroyed, only converted from one form to another

Question 10

chemical potential energy

Answer 10

energy stored in chemical compounds that can be released during chemical reactions

Question 11

2nd Law of Thermodynamics

Answer 11

entropy increases in a closed system

Question 12

entropy

Answer 12

s; energy that cannot be harnessed to do work; chaos

Question 13

enthalpy

Answer 13

h; heat content of a system

Question 14

heat

Answer 14

q; transfer of energy from warmer objects to cooler ones

Question 15

temperature

Answer 15

average kinetic energy of particles at a given time

Question 16

delta H

Answer 16

change in enthalpy of a system

Question 17

endothermic reaction

Answer 17

reaction where energy is added to produce products; +delta H

Question 18

exothermic reaction

Answer 18

reaction where energy is released when products are formed; -delta H

Question 19

joule

Answer 19

J; SI unit for heat and energy

Question 20

kilojoule

Answer 20

kJ; 1000J/1 kJ

Question 21

calorie

Answer 21

cal; amount of energy required to raise the temperature of 1 gram of water 1 °C

Question 22

Calorie

Answer 22

nutritional calorie; Cal; kCal; 1000cal/1 Cal

Question 23

joules to calorie ratio

Answer 23

4.184 J/ 1 cal

Question 24

specific heat

Answer 24

c; amount of energy required to raise the temperature of 1 gram of any substance 1 °C

Question 25

specific heat of water

Answer 25

4.184 J/(gx°C)

Question 26

specific heat equation

Answer 26

q = c x m x delta t

Question 27

thermochemistry

Answer 27

study of energy changes in chemical reactions and phase changes

Question 28

delta H of a reaction equation

Answer 28

(delta H of products) - (delta H of reactants)

Question 29

positive delta H of fusion

Answer 29

melting, solid to liquid

Question 30

positive delta H of vaporization

Answer 30

boiling, liquid to gas

Question 31

negative delta H of solidification

Answer 31

freezing, liquid to solid

Question 32

negative delta H of condensation

Answer 32

gas to liquid

Question 33

standard enthalpy of formation

Answer 33

the change in energy when one mole of a substance forms

Question 34

the standard enthalpy of formation of all free elements

Answer 34

0.0 kJ/mol

Question 35

the standard enthalpy of formation of the reaction

Answer 35

the standard enthalpy of products - reactants