What is the rate of reaction?
The rate at which reactants are used up or products are formed in a chemical reaction.
Based off of collision theory, what is required for a reaction to occur?
Particles must collide, have minimum energy (activation energy), and be oriented correctly for a reaction to occur.
What is a successful collision?
A collision that results in product formation.
What is an unsuccessful collision?
A collision that does not result in products.
How can the rate of reaction be increased (collision theory) ?
By increasing the number of productive collisions per unit time.
What are the factors affecting the rate of homogenous reactions?
Concentration of reactants, catalysts, and temperature.
What additional factors affect heterogeneous reactions?
Surface area of reactants and rate of stirring, in addition to concentration, catalysts, and temperature.
How does increasing concentration affect reaction rate?
More particles per unit volume/unit space lead to more collisions per unit time, increasing the rate of reaction.
How does increasing surface area affect reaction rate?
More exposed reactant particles increase collisions per unit time, so reaction rate increases.
What is activation energy?
The minimum energy particles must have for a chemical reaction to occur.
Why does increasing temperature increase reaction rate?
Particles have higher kinetic energy, more exceed activation energy, and more successful collisions occur per unit time.
Why does a high activation energy make a reaction unlikely?
Few particles have enough energy for a successful collision.
How do catalysts increase reaction rate?
By lowering the activation energy, allowing more particles to successfully collide per unit time, thus increased RR
What is enthalpy?
A measure of the total energy of a substance or system.
Can enthalpy be measured directly?
No, only changes in enthalpy (∆H) can be measured.
What is ∆H and its units?
Change in enthalpy, measured in kJ mol⁻¹.
How is ∆H calculated?
∆H = ∑∆H products - ∑∆H reactants.
What characterizes an endothermic reaction?
Heat is absorbed, products have more energy than reactants, ∆H is positive.
What characterizes an exothermic reaction?
Heat is released, reactants have more energy than products, ∆H is negative.
What is entropy?
A measure of randomness, chaos, or lack of order in a system.
What two drives determine spontaneity of a reaction?
Enthalpy (energy change) and entropy (randomness).
How is Gibbs free energy used to predict spontaneity?
∆G < 0 means forward reaction is spontaneous; ∆G > 0 means reverse is spontaneous.
How does entropy affect reaction direction?
Positive entropy change favours the forward reaction, negative favours the reverse.
What role does chlorophyll play in photosynthesis?
It acts as a catalyst, lowering energy required for the reaction.
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Mod 5 topic 1 - Static/Dynamic Eqlm36
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Mod 5 topic 326
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Mod 5 Topic 430
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Mod 6 Topic 129
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Mod 6 Topic 2 - Using Bronsted Lowry66
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Mod 6 Topic 3 - Quantitative Analysis55
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Mod 7 - Nomenclature70
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Mod 7 - Hydrocarbons57
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Mod 7 - Reactions Involving Hydrocarbons62
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Mod 7 - Alcohols95
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Mod 7 - Organic Acid/Base Reactions58
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Mod 7 - Polymers33
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Mod 5 AT69
