F3 Chapter 5 Thermochemistry(Intro 1)

Diagram shows reaction between sodium and water. The reaction is

The photo shows an application of thermal reaction to repair cracked or broken rails. Describe the application of the thermal reaction.

In the thermal reaction, the heating of iron(III) oxide and aluminum produces iron. The ( exothermic , endothermic ) reaction that takes place (releases , absorbes ) a lot of heat and ( melts , cools ) the iron. This molten iron is used to repair the crack part or reconnect the iron rails.

How does this cool pack function to lower an individual’s body temperature during fever?

• When a cold pack is squeezed, thin plastic separating water from solid ammonium nitrate will be torn.

• These chemicals then dissolve in water which is an ( exothermic , endothermic ) reaction.

• This causes the temperature of the pack to ( increases , decrease ).

Diagram below shows a polytrene cup used in an experiment to compare and contrast exothermic and endothermic reactions. Explain one advantage of using a polystyrene cup in this experiment.

Diagram below shows a polytrene cup used in an experiment to compare and contrast exothermic and endothermic reactions.

• Polystyrene is a good ( insulator , conductor )

•Heat change between the content of the cup and the surroundings is ( minimal , maximum )

• The temperature of the mixture in the cup can be measured accurately