Energy Profile Diagram

Which of the following is/are the fundamental idea(s) of collision theory?

• Molecules react by colliding together

• In a large sample, the greater the number of effective collisions, and the faster the rate of reaction

• The effective collisions must occur with certain minimum amounts of energy 

• All of these.

Tags

NGSS.HS-PS1-5

Which factors increase the rate of a reaction?

• increasing temperature

• increasing surface area

• increasing concentration.

• all of these.

Tags

NGSS.HS-PS1-5

 Why does a higher temperature increase the rate of a reaction?

• it increases both the frequency and energy of particle collisions

• it only increases the frequency of particle collisions

• it only increases the energy of particle collisions

• it reduces the activation energy of the reaction

Tags

NGSS.HS-PS1-5

Consider these two reactions,

Equation 1, Ca(OH)_{2 (aq)} + 2HNO_{3 (aq)} —> Ca(NO₃)_{2 (aq)} + 2H₂O _(l)

 

Equation 2, C(s) + H₂O(g) —> CO(g) + H₂(g)

Which are heterogenous reaction(s)?

• Equation 1

• Equation 2

• Equation 1 + 2

• Neither.

What letter represents the sum of (represented as Σ) the energy of the products?

• A
• B
• C
• D

Answer explanation

D - this is the energy contained within the bonds of the products being formed.

Tags

NGSS.HS-PS1-4

Based on the information provided which label below can we use to describe this reaction?

• Endothermic
• Exothermic
• Heterogenous

• Homogenous

Tags

NGSS.HS-PS1-4

What letter represents the activation energy?

• A
• B
• C
• D

Answer explanation

Look for the label that travels from the energy of the reactants to the highest peak of the energy profile diagram - this is the activation energy (E_a). In this diagram it was 'A'.

Tags

NGSS.HS-PS1-4

Based on what we know from the graph opposite, how could we classify this reaction?

• endothermic 
• exothermic
• combustion

• synthesis

Tags

NGSS.HS-PS1-4

What is the value of the activation energy in this diagram?

• 40 kJ
• 20 kJ
• 100 kJ
• 60 kJ

Tags

NGSS.HS-PS1-4

Which letter represents the activation energy?

• B
• E
• C
• D

Tags

NGSS.HS-PS1-4