C5 - Energy changes

Question 1

What is an exothermic reaction?

Answer 1

a reaction where energy is released into the surroundings.

Question 2

What is an endothermic reaction?

Answer 2

a reaction where energy is taken in from the surroundings.

Question 3

What are some examples of an exothermic reaction?

Answer 3

combustion, neutralisation, oxidation

Question 4

what are some examples of an endothermic reaction?

Answer 4

photosynthesis, thermal decomposition, dissolving salt in water

Question 5

When barium hydroxide and ammonium chloride react, the temperature of the mixture decreases. What kind of reaction is this

Answer 5

endothermic

Question 6

Which of the following should be used to contain the solution when investigating energy change?
a) a polystyrene cup
b) a glass beaker
c) a measuring cylinder

Answer 6

a) a polystyrene cup

Question 7

Which type of process is bond breaking?

Answer 7

endothermic

Question 8

Which type of process is bond forming?

Answer 8

exothermic

Question 9

Does an endothermic reaction have a higher or lower activation rate than exothermic?

Answer 9

higher

Question 10

Does an exothermic reaction have a higher or lower activation rate than endothermic?

Answer 10

lower

Question 11

What type of reaction is in a hand warmer?

Answer 11

exothermic

Question 12

What type of energy is in an ice pack?

Answer 12

endothermic

Question 13

What term is given to a reaction which transfers heat to the surroundings?

Answer 13

exothermic

Question 14

What piece of equipment is used to measure temperature?

Answer 14

thermometer

Question 15

What type of reaction is this:
The starting temperature is 36°C and the end temperature is 23°C.

Answer 15

endothermic

Question 16

What type of reaction is this
The starting temperature is 16°C and the end temperature is 20°C.

Answer 16

exothermic

Question 17

if the temperature change in a reaction is 12°C, what type of reaction is it?

Answer 17

exothermic

Question 18

if the temperature change in a reaction is -9°C, what type of reaction is it?

Answer 18

endothermic

Question 19

During a chemical reaction the starting substances are called __________.

Answer 19

reactants

Question 20

The starting substances react to produce __________.

Answer 20

products

Question 21

During a chemical reaction, mass cannot be __________ or destroyed. It is __________

Answer 21

created, conserved