Chem Unit 6 Review

What is the study of rates of reactions and how they occur?

(a)  

Tags

NGSS.HS-PS1-5

Which of the following are needed for a reaction to occur?

• Particles need to collide.

• Particles need to be orientated correctly.

• Particles need a minimum amount of energy to make/break bonds.

• Particles can only interact with themselves.

Tags

NGSS.HS-PS1-5

Given reactions A & B (assuming the particles are colliding and orientated correctly) which reaction will occur at a faster rate and why?

• A. At lower temperatures more energy is conserved and not lost to moving around.

• A. Particles have less heat/energy and will less likely miss a collision.

• B. Particles are reacting in a smaller volume with a higher chance of collision.

• B. Particles have more heat/energy to make/break bonds.

Tags

NGSS.HS-PS1-5

(a)   is the tendency for disorder in a system. (randomness of particles)

​ (b)   is the amount of energy/heat in a system.

• Entropy
• Enthalpy

Tags

NGSS.HS-PS3-4

Rank the following particles from lowest to greatest entropy.

(Ordered --> Disordered)

• 
• 
• 
• 

Answer explanation

Large ball would have the most order to it. Balls farthest apart would be the most random.

Rank the following particles from lowest to greatest enthalpy.

('coldest' --> 'warmest')

• 
• 
• 

Answer explanation

Ice < Water < Steam

low enthalpy --> high enthalpy

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

Entropy favors (a)   lowering the energy in the system.

Enthalpy favors ​ (b)   energy levels making it more stable.

• disorder
• lower
• order
• higher

Answer explanation

Entropy (randomness): disorder > order

Enthalpy (energy): low > high

Tags

NGSS.HS-PS3-4

Select all the intermediate products in the following reaction:

N2 + 3 H2 --> 2 NH3

• 2 N

• H2

• NH3

• 6 H

Answer explanation

Break down all molecules into their individual atoms.

Select all the intermediate products in the following reaction:

C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O

• 6 C

• 12 H

• 6 CO

• 18 O

Answer explanation

Break down all molecules into their individual atoms.

Tags

NGSS.HS-LS1-7

Label all of the parts of the reaction curve.

a

b

c

d

e

Activation Energy (Ea)

Intermediate Steps

Reactants

Change in enthalpy (∆H)

Products

Tags

NGSS.HS-PS1-4