Endothermic and exothermic process (1)

Post on 24-May-2015

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Transcript of Endothermic and exothermic process (1)

What is DATA LOGGING ?

Process of using computer to collect data through sensors, analyze data and save the output the

results of the collection and analysis

Data : A collection of resultsData Logging : Process handling data by using

computer technology

ELEMENTS OF DATA LOGGING

Endothermic and exothermic process

engage

a b

Sensor Data collector

Empower

Carry out experiment

Result Solution of copper (II) sulphate,

Solution of anhydrous copper (II) sulphate

• Is the enthalpy change for this reaction exothermic or endothermic?

• What sign should the enthalpy change have?

• What is the equation for this reaction?

• What bonds are being broken and formed in this reaction?

• What is this enthalpy change called?

• How can we make a triangle between these reactions?

Enhance

Cold packs and putting ice in towel causes a cooling

effect on their person’s head and temporarily relieve

the pain and fever. Explain.

a) Cold Pack• When the cold pack is used, the chemicals

inside the pack are made to react with each other and this reaction is highly endothermic in nature.

• Endothermic reactions involve the absorption of heat.

• The ammonium nitrate mixing with the water creates cold. The temperature of cold packs can reach back to normal temperature.

• The heat energy is taken into the system from the surrounding. The surrounding in this case is the person’s head.

Extension

Production of Ammonia Gas :

N2 (g) + 3H2 (g) ↔ 2NH3 (g)

What will happen to the reaction if we increase the concentration the temperature of the reactant mixture?

• If the temperature of a reaction mixture is increase, the

equilibrium will shift to decrease the temperature.

• Based on Le Chatelier’s Principle which stated that if a

chemical system at equilibrium experiences a change in

concentration, temperature or total pressure, the

equilibrium will shift in order to minimize that changes a

new equilibrium is established.

• So, if we increase the temperature, the equilibrium will

shift to the reactant part which is left.

• So, the reaction will undergo endothermic reaction as it

use up heat energy.

• Ammonia will broken down into hydrogen and nitrogen

gas. An increase in temperature will decrease the yield

of ammonia , NH3.