CHEM 100 LAB: Week 11 Reaction Mechanics

CHEM 100 LAB

What is a Replacement Reaction?

An element reacts with a compound and replaces another element

What Determines whether a Metal can Replace Another Metal?

The reacting metal must be more active

What is the Activity of a Metal?

Its relative ability to lose electrons

What is an Activity Series?

A list of metals in order of activity

More Active Metals are Better at

Losing electrons

What does Metal + Water Produce?

Metal hydroxide and hydrogen gas

How do you Test if Base formed in Water Reaction

Litmus paper

How do you Test for Hydrogen Gas?

Splint test

What Metal is Most Active?

The one that reacts in cold water

A Metal that Reacts in Hot Water but Not Cold Water is

Less active than metals that react in cold water

Least Active Metals React with

Neither water nor HCI

According to Collision Theory, Reaction Rate depends on

Number and effectiveness of collisions

What Happens to the Reaction Rate when Particle Size Decreases?

Reaction rate increases

Why does Smaller Particle Size Increase Reaction Rate?

Greater surface area/More collisions

What Happens to the Reaction Rate when Temperature Increases?

Reaction rate increases

Why does Temperature Increase Reaction Rate?

Particles move faster and collide more often/with more energy

What Happens when Concentration Increases?

Reaction rate increases

Why does Concentration Increase Reaction Rate?

More particles present, more collisions

What is a Catalyst?

A substance that increases reaction rate

How does a Catalyst Increase Rate?

Lowering activation energy and Increasing effective collisions

Is a Catalyst Consumed in the Reaction

No

What is a Reversible Reaction?

A reaction where forward and reverse reactions occur simultaneously

At Equilibrium, Concentrations are

Constant

What does it mean if Equilibrium shifts Right?

Product concentration increases

What does it mean if Equilibrium shifts Left?

Reactant concentration increases

What Happens when Stress is Applied to Equilibrium?

System shifts to oppose the stress

What Color is Fe(SCN)3

Red

What indicates Equilibrium shifted Right in FeCl3/KSCN system?

Darker red color

What Indicates Equilibrium shifted Left?

Lighter red color

What is Le Chatelier’s Principle?

If a system at equilibrium is subjected to a change, the system responds to counteract the change

If Reactants are added, Equilibrium shifts

Right

If Products are added, Equilibrium shifts

Left

What does it Mean if Equilibrium lies to the Right?

More products are present than reactants at equilibrium

What does it Mean if Equilibrium lies to the Left?

More reactants are present than products at equilibrium

What is Dynamic Equilibrium/Equilibrium?

A state in which forward and reverse reactions continue occurring at equal rates

At Equilibrium, are All Species Present?

Yes

At Equilibrium, are Reactant and Product amounts Equal?

No, they remain constant but are not necessarily equal

General Form of Single Replacement Reaction

A + BX → B + AX

When will Single Replacement Occur?

Only if A is more active than B

What if B is More Active than A?

No reaction occurs

Any more Active Metal can Replace

A less active metal in an ionic compound

Most Active Metals React with

Cold water

Slightly Less Active Metals React with

Hot water

Less Active Metals React with

Acid

What makes a Collision Effective?

Sufficient energy and correct orientation

Increasing Surface Area and Concentration both do what to the Reaction Rate?

Increase the number of collisions

Increasing Temperature does what to the Reaction Rate?

Increases the number and effectiveness of collisions

Adding a Catalyst does what to the Reaction Rate?

Increases the effectiveness of collisions