C3.2 - Energy Transfer

Question 1

what do exothermic reactions release

Answer 1

exothermic reactions release energy (they get hot)

Question 2

what do endothermic reactions absorb

Answer 2

exothermic reactions absorb energy (they get cold)

Question 3

what are some examples of exothermic reactions

Answer 3

combustion, welding reaction, respirations, reactions of metals with acids, the thermit process

Question 4

what are some examples of endothermic reactions

Answer 4

photosynthesis, thermal decomposition, some types of electrolysis, sherbet, bath bombs

Question 5

in an exothermic reaction, does the temperature (of surroundings) go up or down

Answer 5

the temperature goes up

Question 6

in an endothermic reaction, does the temperature (of surroundings) go up or down

Answer 6

the temperature goes down

Question 7

what happens to chemicals if they are heated strongly enough

Answer 7

they break up (decompose) - which means that energy is needed to break chemical bonds (endothermic process)

Question 8

what happens if bond breaking is exothermic

Answer 8

energy is released when chemical bonds are made

Question 9

what is activation energy

Answer 9

the certain amount of energy reactions need to get started

Question 10

what is bond energy

Answer 10

the amount of energy needed to break or make a bond

Question 11

what is the equation for total energy change

Answer 11

total energy change = energy in - energy out

Question 12

is bond breaking an exothermic or an endothermic reaction

Answer 12

endothermic

Question 13

is bond making an exothermic or an endothermic reaction

Answer 13

exothermic

Question 14

how can activation energy be supplied

Answer 14

sparks, flames, heating, electrical energy