What name and sympol is given to the overall change in energy at constant pressure during a chemical reaction.

• Potential difference , ΔV

• Temprature change , ΔT

• Entropy change , ΔS

Which of these statement does not describe the converstion of energy in a chemical reaction ?                             

• Energy is neither created nor destroyed during a chemical reaction.

• The energy contained in the bonds of rectant molecules always equal the energy contained in the bonds of the product molecules. 

• If the energy of the system increase the energyof the surrounding decrease by the exact same amount

• Energy can only be transferred from one form to another.

Why do chemical reactions usually involve a change in energy?

• The process of making or breaking bonds during a chemical reaction absorbs and releases energy.

• The process of splitting the nucleus of an atom releases large amounts of energy.

• The nuclei move faster during chemical reactions and so require more energy.

• In chemical reactions, atoms are destroyed and converted into energy.

Which of the following is not a type of energy that a chemical reaction may produce?

• Light

• Electric

• Color

• Chemical

Fuels can also be used to provide energy. Which of the following fuels does not produce energy through a chemical reaction?

• Biofuels

• Fuel cells

• Nuclear fuel

• Fossil fuel

Many chemical reactions are used to provide energy in the form of heat. However, what type of useful energy do the chemical reactions inside batteries provide?

• Sound

• Electicity

• Light

• Gravitational

Diphenyl oxalate, hydrogen peroxide, and rhodamine A are mixed together in a plastic tube. After a few seconds, the plastic tube begins to feel warm, and the resulting mixture starts to glow a bright-red colour. Which types of energy are produced by the mixture?

• Light only

• Heat only

• Heat and light

• Light and electric

The opposite graphical figure represents the thermal change which occurs during a chemical reaction, What is the value of ∆H of this reaction?

• -120kj

• -30kj

• +30kj

• +120kj

The molar bond energy of F₂ is 159 kJ/mol.Calculate the energy of one F-F bond

• 1.65 x 10^-19 J

• 2.64 x 10^-19 J

• 9.58 x 10^-19 J

• 3.78 x 10^-19 J

What is Avogadro’s number to 2 decimal places

• 6.02 x 10²³

• 6.71 x 10¹⁴

• 10⁹

• 3.14