Energetics Ch5

The energy level diagram for the reaction between magnesium and hydrochloric acid is shown.

• Energy is given out during the reaction

• The products are at a lower energy level than the reactants

• The reaction is endothermic.

Which reaction is endothermic?

• acid neutralising alkali causing a temperature increase

• adding magnesium to hydrochloric acid

• calcium carbonate decomposing when heated combustion of fossil fuels

Some white anhydrous copper(II) sulfate powder is put into a beaker of water and stirred. What would show that the process was exothermic?

• A blue solution is formed

• The beaker feels cooler

• The beaker feels warmer

Exothermic reactions are ones that.....

• Release energy to the surroundings

• Absorb energy from the surroundings

• Remain at a constant temperature

• Decrease in temperature

Neutralisation reactions always....

• stay the same temperature

• decrease in temperature

• increase in temperature

• Increase at first and then decrease at the end

Adding energy to get a reaction started is.....

• Activation energy

• Catalytic

• never needed

• needed for breaking bonds

Combustion reactions are ......

• always resulting in an increase in temperature

• never decrease in temperature

• always result in a zero enthalpy change

• never have temperature increases

An example of an endothermic reaction is......

• burning

• neutralisation

• thermal decomposition

• metal and acid reactions

endothermic reactions ........

• have more energy in their products

• have less energy in their products

• have more energy in their reactants

• have the same amount of energy in reactants and products

The amount of energy change in a reaction is known as.....

• endothermic

• Delta H

• exothermic

• Mole/Mass/delta H