Chemistry - Test 1

Question 1

Explain the 5 particle theories of matter

Answer 1

1. All matter is made of extremely tiny particles
2. All pure substances are made of their own kind of particle
3. All particles are moving
4. Particles at higher temperatures move faster than those at lower temperatures.
5. Particles are attracted to each other

Question 2

Explain collision theory

Answer 2

Collision theory explains why different reactions occur at different rates.

Collision theory states that for a chemical reaction to take place, the reaction particles must collide with one another.

Question 3

Explain how temperature can increase or decrease reaction rate

Answer 3

if a reaction is heated up it causes the particles move more quick. This causes an increase in reaction rate.

Question 4

Explain how concentration can increase or decrease reaction rate

Answer 4

When the concentration of all the reactant increases, more molecules or ions interact to form new compounds, and the rate of reaction increases.

Question 5

Explain how surface area can increase or decrease reaction rate

Answer 5

Increasing surface area, increases exposure of the particles to the outside layer of the substance they are reacting with.
By crushing, cutting or refining a substance into smaller pieces, the surface area is increased and so is the rate of reaction. For the reverse effect, you can use larger pieces of the substance.

Question 6

What is a catalyst? Explain how it works.

Answer 6

Catalysts can be used to change the rate of reactions.
Catalysts don’t get consumed in a reaction and retain the same mass at the end.
They maintain their structure and mass throughout the entire reaction

Question 7

What happens to a catalyst during the reaction?

Answer 7

It will increase the reaction rate without getting consumed.

Question 8

What is an enzyme, draw the lock and key model of an enzyme