Exit - U5.4

Methane (CH4), the gas used for Bunsen burners, doesn’t react with oxygen in the air until a striker/flame is brought near to the Bunsen burner. Explain the role of the striker/flame.

• Increases the heat

• supplies the activation energy

• Lowers the activation energy

• Increases the rate of the reaction

Methane (CH₄), the gas used for Bunsen burners, doesn’t react with oxygen in the air until a striker/flame is brought near to the Bunsen burner. What is the energy provided by the striker/flame used for?

• Breaking bonds of CH₄ and O₂

• Decreasing the rate of the reaction

• Lowering the activation energy

• Increasing the rate of the reaction

Given the reaction: 2 NO₂ (g)----->N₂O₄ (g) the rate of reaction was slow with 2.00 moles of NO2 in a 2.00 L

container at 1 atm and 285K. Suggest three different ways in increase the rate for this reaction, and

explain, with reference to collision theory, how each will alter the rate of reaction.

• Increase the concentration of NO₂

• Increasing the temperature

• Lowering the volume

• Lowering the temperature

A scientist calculated that 10% of the collisions that occur for a specific reaction are in the correct

orientation for a reaction to occur, but they found experimentally that the actual number of reactions that occurred was much lower than their calculation. Which factor did they forget to account for?

• Not all particles have sufficient energy

• Not all particles collide

• Temperature

• Pressure

The diagram shows the Maxwell−Boltzmann distribution of molecular energies in a gas at two different temperatures.

Which letter represents the most probable energy of the molecules at the higher temperature?

• A

• B

• C

• D

Which of the following pairs of Maxwell–Boltzmann distribution curves best represents the distribution of kinetic energy for particles at two different temperatures?

Note: dashed line = higher temperature, solid line = lower temperature.

• 
• 
• 
•