Chemical Reactions and Equilibrium

Chemical Reactions and Equilibrium

Multiple Choice

Which letter corresponds to the activation energy of the forward reaction?

• A
• B
• C
• D

Multiple Choice

What is the activation energy?

• The energy of the products
• The energy of the reactants
• The minimum energy needed by the reactants to form the products.
• The energy lost in the reaction

Activation Energy

the minimum energy required to begin a chemical reaction

Multiple Select

What can affect the rate of a chemical reaction? (check all that apply)

• temp

• surface area

• concentration

• catalysts

• color

rxn rate factors

• temp

• surface area

• concentration

• catalyst

Multiple Choice

Which of the reaction pathway shows the catalysed reaction?

• 1

• 2

• 3

• 4

Multiple Choice

What do you call the energy that is required to start a reaction?

• Alternative energy

• Activation energy

• Atmospheric energy

Multiple Choice

What does catalyst do to a reaction?

• Slows down the reaction

• Nothing changes

• Speeds up the reaction

Catalysts

• A substance that increases the rate of a reaction without being consumed in the reaction

• reduces the activation energy of a rxn

Collision Theory

• rxn cannot take place unless

• 1. they collide

• 2. enough energy is available

• 3. they are in the correct orientation

Multiple Choice

When surface area is decreased the rate of reaction...

• Decreases, because there are LESS possible sites for correct collisions

• Increases, because there are LESS possible sites for correct collisions

• Decreases, because there are MORE possible sites for correct collisions

• Increases, because there are MORE possible sites for correct collisions

Multiple Choice

More collisions correspond to a: 

• Faster reaction rate  
• Slower reaction rate
• Constant reaction rate 
• None of the above

Multiple Choice

What criteria must be met for reactant collisions to result in a successful product?

• The reactants must collide with each other

• The reactants must collide with enough energy and be in the right positions

• The reactants must have enough energy to form the activated complex

Reaction Rate Calculations

 $R=\frac{\Delta C}{\Delta T}$  

Fill in the Blank

In the reaction H₂O₂(aq) → H₂O(l) + ½ O₂(g), the initial concentration of H₂O₂ is 0.2546 M, and the initial rate of reaction is 9.32×10^–4 M s^–1. What will be [H₂O₂] at t = 35 s? hundreths

Reversible rxns and Equilibrium

• Dynamic equilibrium

• equal in the formation of reactants and products not in concentrations

Formula K_eq

capitals are Molar concentrations

lower case are #moles in a balanced eq