Four different fuels are used to heat a beaker of water, for the same amount of time, using the apparatus shown.
The initial temperature of the water and the temperature after heating by the fuel are recorded.
Which fuel releases the most heat energy?
initial temperature
temperature after
heating
17
46
24
52
26
61
30
62
Which row describes the changes that occur in an endothermic reaction?
energy change
temperature
energy given out to
the surroundings
decreases
energy given out to
the surroundings
increases
energy taken in from
the surroundings
decreases
energy taken in from
the surroundings
increases
Which reaction pathway diagram shows the reaction that will give out the most energy?
The scale on the y-axis is the same in each diagram.
Two different experiments are done to find the enthalpy change, , of each reaction.
The temperature of each reaction mixture is measured at the beginning of the reaction and after 3 minutes.
experiment 2
experiment 1
Which row gives the correct sign for the value of for each experiment and identifies if the reaction is endothermic or exothermic?
experiment 1
experiment 2
negative and endothermic
positive and exothermic
negative and exothermic
positive and endothermic
positive and endothermic
negative and exothermic
positive and exothermic
negative and endothermic