C5: TEMP CHANGE

Question 1

What is an exothermic reaction?

Answer 1

a reaction that releases heat energy into the surroundings (eg: combustion)

Question 2

What is an endothermic reaction?

Answer 2

a reaction that takes in heat energy from the surroundings (eg: instant ice pack)

Question 3

What type of reaction is breaking bonds?

Answer 3

endothermic

Question 4

What type of reaction is making bonds?

Answer 4

exothermic

Question 5

RP: temp change

Answer 5

-measure 50cm^3 NaOH into a polystyrene cup
-measure starting temp of solution
-add 10cm^3 HCl to the polystyrene cup and add a lid
-stir mixture
-measure and record highest temp of the mixture
-calculate temp change (highest - lowest)
-repeat with different volumes of NaOH

Question 6

What are the variables in the temp change practical?

Answer 6

IV - volume of NaOH
DV - max temp
CVs:
-conc. of HCl
-volume of HCl
-conc. of NaOH
-time