ENERGETICS

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

Tags

NGSS.HS-PS1-4

Which statements about exothermic and endothermic reactions are correct?

• During an exothermic reaction, heat is given out

• The temperature of an endothermic reaction goes up because heat is taken in

• Burning methane in the air is an exothermic reaction

Which is an endothermic process?

• Burning hydrogen

• Distilling petroleum

• Reacting potassium with water

• Using petrol in a motor car engine

A power station was designed to burn gaseous fuels only. Which two substances could be used?

• carbon dioxide and hydrogen

• carbon dioxide and 235U

• Hydrogen and Methane

Which fuel does not produce carbon dioxide when it burns?

• Coal

• Hydrogen

• Methane

Which substance is not a fossil fuel?

• coal

• kerosene

• wood

Statement 1 Hydrogen is used as a fuel.

Statement 2 When hydrogen burns in the air to form water, heat energy is produced.

Which is correct?

• Both statements are correct and statement 2 explains statement 1

• Both statements are correct but statement 2 does not explain statement 1

• C Statement 1 is correct but statement 2 is incorrect

. Which substance does not require oxygen in order to produce energy?

• Coal

• 235U

• Natural gas

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