Chemistry

Question 1

What is a Rate of Reaction?

Answer 1

Is Quantity of reactant used over time taken
or
Quantity of product formed over time taken

Question 2

What different units can there be for measuring rates of reactions?

Answer 2

Mass is grams —> g/s
Volume in cm3 —> cm3/s

Question 3

What factors can affect the rate of reaction?

Answer 3

• Constant Stirring - This makes the particles have more kinetic energy so makes it Faster
• Replace Acid with Water - This means there is fewer particles per cm3 so it becomes Slower
• Reactant Folded - This decreases its surface area meaning it have less frequent collisions and is therefore Slower
• Half the Volume of Acid - This means there is fewer particles resulting in less frequent collisions so it becomes Slower
• Acid at a Hotter Temp. - This gives the particles more kinetic energy so makes it Faster

Question 4

What is Collision Theory?

Answer 4

The Rules of a Reaction that state:
- If the particles are moving to slow they will not react and bounce of each other
- If the particles are facing the wrong way they will not react and bounce of each other

• BUT if they collide in the correct direction/angle and with enough energy there will be a successful collision and a Chemical Reaction will occur

Question 5

How does Temperature Affect the Rate of Reaction?

Answer 5

The Hotter the Reactant or Liquid the Faster the Reaction will be as the heat increases the Kinetic Energy in the particles making them faster which means there if more likelihood of the particles having a successful collision and therefore means the chemical reaction/ rate of reaction is faster

Question 6

How is the Surface Area of a Solid Increased?

Answer 6

By making it into smaller/finer pieces e.g. Marble Chips —> Marble Powder

Question 7

How does Surface Area Affect the Rate of Reaction?

Answer 7

By increasing the surface area of the Reactant it means there are more particles exposed and therefore makes the possibility of a successful reaction increase as well as there are more particles that can react. This makes the rate of reaction faster as there are more reactions taking place because of this increase in surface area