Energy Changes

Question 1

what is energy not?

Answer 1

not a mass, not matter, not a substance, does not take up space

Question 2

energy is?

Answer 2

a measure of the ability to cause change to occur

Question 3

what process releases energy?

Answer 3

exothermic

Question 4

what process has flames?

Answer 4

exothermic

Question 5

what process creates products that are hotter than the reactants?

Answer 5

exothermic

Question 6

who is the worst teacher employed at Garnet Valley?

Answer 6

Mrs. Stein

Question 7

what does a molecular covalent compound react with/ produce?/ what type of reaction is it?

Answer 7

reacts with Oxygen/ produces C02 and water. and also heat, light, and flames. Exothermic

Question 8

what type of reactions produce heat and light, but no flames?

Answer 8

when a metal or elemental metal reacts with oxygen. exothermic

Question 9

what type of changes are related to exothermic changes?

Answer 9

big changes in matter (fire)

Question 10

what is the remaining ash and charred fuel from a fire from?

Answer 10

they are the results of reactants that did not react completely

Question 11

what distinguishes an exothermic process?

Answer 11

flames, heat

Question 12

how is the glowing yellow color of a wood fire caused?

Answer 12

particles of carbon are carried into the air by the gaseous products of the exothermic reaction

Question 13

what are changes of matter accompanied by?

Answer 13

a change in matter

Question 14

what is heat?

Answer 14

the transfer of energy between 2 objects, due to temp differences

Question 15

what is the system?/ what is it used for

Answer 15

the matter you are focusing on/ its used to represent where heat is transferring from or transferring to (substance)

Question 16

what is the surroundings?

Answer 16

is anything else that surrounds the system (the environment. beaker, thermometer)

Question 17

how are chemical changes categorized?

Answer 17

by the direction of heat transfer

Question 18

what is endothermic?

Answer 18

when heat if transferred from the surrounding to the system

Question 19

cold is experienced with what process?

Answer 19

exothermic

Question 20

what is kinetic energy?

Answer 20

the energy of motion

Question 21

what is a reflection of average kinetic energy of a sample?

Answer 21

temperature

Question 22

if the products of a reaction are hotter than the reactants, they must be __________

Answer 22

moving faster

Question 23

what reaction launches a space shuttle?

Answer 23

reaction between H2 and O2, which produces H2O, and is very exothermic

Question 24

hotter products mean _____ particles

Answer 24

faster moving

Question 25

colder products mean _______ particles

Answer 25

slower moving

Question 26

what are the 3 main ways heat is transfered?

Answer 26

- conduction - convection - radiation

Question 27

what is conduction heat transfer

Answer 27

takes place when a substance transfers heat to another substance or object that it is in contact with. ex: handle of a frying pan getting hot bc the pan is hot

Question 28

what is convection heat transfer

Answer 28

takes place when a warm substance changes location, such as when warm air rises

Question 29

what is radiation heat transfer

Answer 29

takes place when electromagnetic waves carry energy from an energy source, ex: the sun

Question 30

what does the sensation of hot or cold depend on?

Answer 30

which direction heat is transferred

Question 31

what is thermal equilibrium?

Answer 31

when 2 objects reach the same temperature

Question 32

the first law of thermodynamics

Answer 32

states that energy is always conserved. heat is always transferred from a hotter object, to cooler. likewise you can't create energy

Question 33

second law of thermodynamics

Answer 33

states that energy tends to disperse, or spread out. energy transfers from a hot object, to a colder object. ex: a fire, and how you can feel the heat of it far away. entropy of a system tends to increase over time.

Question 34

what is entropy

Answer 34

means that energy tends to become more dispersed and disordered rather than collected and ordered. Ex: spraying perfume, it does everywhere, you can't get it back into the bottle

Question 35

thermal energy

Answer 35

describes the total amount of energy in the particles of a sample.

Question 36

what is the thermal energy dependent on?

Answer 36

the temp of the sample and the number of particles in the sample (mass).

Question 37

what is a calorie

Answer 37

is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius

Question 38

what is the equation used to measure heat transfer?

Answer 38

Q= (m)x(1cal/gXdegreesC)x(Temp. Initial- Temp. Final). | Use distributive property

Question 39

what is the difference between temp. and heat?

Answer 39

the temp is a measure of the avg kinetic energy of its particles. heat is a process of energy transfer to or from a sample of matter

Question 40

what is specific heat capacity ?

Answer 40

the heat required to raise the temp of 1g of a substance by 1 degree Celsius. every substance is different (aluminum pot of water)

Question 41

substances that are polar tend to have ______ capacities / what does it mean?

Answer 41

high specific heat/ means that molecules will have higher specific heat capacities than metals

Question 42

why does water have a high specific heat?

Answer 42

- the molar mass of water is small - water is molecular, and has complex internal movements - water has hydrogen bonds, strong intermolecular `attractions

Question 43

heat of vaporization?

Answer 43

heat required to change 1 gram of a substance from a liquid into a gas

Question 44

heat of fusion

Answer 44

the heat required to change 1 gram of a substance from a solid to a liquid

Question 45

when a substance changes from a solid into a liquid, or liquid into a gas energy is transferred to ____

Answer 45

to the substance from the surroundings

Question 46

when a substance changes phase from a gas to a liquid of from a liquid to a solid, energy is transferred from the ______ to the _____

Answer 46

substance to the surroundings

Question 47

energy spread is during what process

Answer 47

exothermic

Question 48

matter spread occurs during what process

Answer 48

endothermic

Question 49

during an exothermic reaction, what is felt?

Answer 49

cold

Question 50

during an endothermic reaction what is felt?

Answer 50

heat

Question 51

endothermic is

Answer 51

gaining heat energy

Question 52

exothermic is

Answer 52

loosing energy