Surface Area and Reaction Rates

Mr. Hammer explains the relationship between reaction rate and surface area. He demonstrates how Lycopodium powder reacts with oxygen, showing that only the surface layer burns while the underlying powder remains unreacted. By dispersing the powder into a mist, the surface area increases, allowing more particles to collide with oxygen, thus speeding up the reaction. The video concludes by emphasizing that increased surface area enhances the likelihood of molecular collisions, thereby accelerating chemical reactions.

What is necessary for atoms or molecules to react with each other?

• They need to be dissolved in water.

• They must be heated to a high temperature.

• They need to collide with each other.

• They must be in a solid state.

In the demonstration, what substance is used to show the reaction with oxygen?

• Sulfur powder

• Copper sulfate

• Lycopodium powder

• Iron filings

Why does only the surface layer of Lycopodium powder react with oxygen?

• The surface layer is denser.

• The surface layer is heated more.

• The surface layer is exposed to oxygen.

• The surface layer is more reactive.

What happens to the Lycopodium powder underneath the surface layer?

• It reacts slowly.

• It evaporates.

• It reacts quickly.

• It remains unreacted.

What is the main factor that limits the reaction of the Lycopodium powder?

• Lack of heat

• Lack of oxygen access

• Lack of light

• Lack of moisture

How can the reaction rate of Lycopodium powder be increased?

• By adding more powder.

• By reducing the amount of oxygen.

• By turning it into a mist.

• By heating it to a higher temperature.

What is the result of spraying Lycopodium powder through a flame?

• The powder becomes non-flammable.

• The reaction rate remains the same.

• The reaction rate decreases.

• The reaction rate increases.

What effect does increasing the surface area have on the reaction rate?

• It decreases the reaction rate.

• It has no effect on the reaction rate.

• It increases the reaction rate.

• It stops the reaction completely.

What is the relationship between surface area and the likelihood of molecular collisions?

• Increased surface area increases collisions.

• Increased surface area decreases collisions.

• Surface area prevents collisions.

• Surface area has no effect on collisions.

What is the key takeaway about surface area and reaction rate?

• Surface area only affects physical reactions.

• Increased surface area increases reaction rate.

• Increased surface area decreases reaction rate.

• Surface area has no impact on reaction rate.