Topic VII: Kinetics and Equilibrium review

How is ΔH determined?

• H (PE)of reactants - H (PE) of products

• H (PE) of reactants + H of (PE) products

• H (PE) of products - H (PE) of reactants

• H (PE) of products + H (PE) of reactants

Tags

NGSS.HS-PS1-4

Which describes an exothermic reaction?

• ΔH is negative and the products have more potential energy than the reactants.

• ΔH is negative and the products have less potential energy than the reactants.

• ΔH is positive and the products have more potential energy than the reactants.

• ΔH is positive and the products have less potential energy than the reactants.

Tags

NGSS.HS-PS1-4

CO₂(g) → CO₂(l) is

• endothermic with increased entropy.

• exothermic with increased entropy.

• endothermic with decreased entropy.

• exothermic with decreased entropy.

Tags

NGSS.HS-PS1-4

How many kJ of heat are absorbed when 2 mol of C₂H₄ are formed?

• 157.2

• 26.2

• 52.4

• 104.8

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Activation energy is required for

• only exothermic chemical reactions

• only endothermic chemical reactions

• all chemical reactions

• both endothermic and exothermic chemical reactions

Tags

NGSS.HS-PS1-4

An inhibitor changes the rate of reaction by increasing the

• activation energy and a catalyst changes the rate of reaction by increasing the activation energy.

• potential energy and a catalyst changes the rate of reaction by increasing the activation energy.

• activation energy and a catalyst changes the rate of reaction by lowering the activation energy.

• activation energy and a catalyst changes the rate of reaction by lowering the potential energy.

Which reaction will most likely occur spontaneously?

• exothermic with decreased entropy

• endothermic with increased entropy

• exothermic with increased entropy

• exothermic with decreased entropy

Tags

NGSS.HS-PS1-4

Which shows a decrease in entropy for each change?

• solid, liquid, gas

• solid, gas, liquid

• gas, solid, liquid

• gas, liquid, solid

Tags

NGSS.HS-PS3-4

2H₂(g) + O₂(g) → 2H₂O(l) would be expected to have a faster reaction rate than Pb²⁺(aq) + S^2-(aq) → PbS(aq).

• true

• false, aqueous solutions already have the substance dissolved in it and the ions separated so there will be more effective collisions.

• false, there is no way to make a valid prediction

Tags

NGSS.HS-PS1-5

In a gaseous system, temperature remaining constant, an increase in pressure will

• decrease the reaction rate

• increase the reaction rate

• increase the activation energy

• decrease the activation energy

Tags

NGSS.HS-PS1-5