AP Chemistry Thermodynamics 2020

Which of the letters (A-D) represents the potential energy of the reactants?

• A
• B
• C
• D

Tags

NGSS.HS-PS1-4

What kind of reaction is this?

• endothermic
• exothermic

Tags

NGSS.HS-PS1-4

žDetermine the energy (in J) required to raise the temperature of 100.0 g of water from 20.0 C to 85.0 C? The specific heat of water is 4.184 J/g°C

• 500 J
• 4,182 J
• 27,196 J
• 27200 J

Tags

NGSS.HS-PS3-1

Refer the the following question:

2N₂ + 3H₂ --> 2NH₃ + 46 kJ

How much energy would be produced if 18.2 g of nitrogen reacted with excess hydrogen?

• 92 kJ

• 0.143 kJ

• 23 kJ

• 15 kJ

Tags

NGSS.HS-PS3-1

What mass of P₄ must be reacted to produce 5905 kJ of energy?
P₄ + 6Cl₂ --> 4PCl₃ + 2439 kJ

• 25.43 g
• 563.0 g
• 2.421 g
• 300.0 g

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

When calcium oxalate dissolves in water, a spontaneous exothermic dissolving process occurs. Which gives the correct signs for the thermodynamic parameters for such a spontaneous reaction?

• ΔG_soln + ΔH_soln + ΔS_soln +

• ΔG_soln - ΔH_soln + ΔS_soln +

• ΔG_soln - ΔH_soln - ΔS_soln +

• ΔG_soln - ΔH_soln - ΔS_soln -

Tags

NGSS.HS-PS1-4

When ammonium nitrate dissolves in water, the solution gets cold. Which is true?

• Reaction is ENDOTHERMIC with positive ΔH
• Reaction is ENDOTHERMIC with -ΔH
• Reaction is EXOTHERMIC with a -ΔH
• Reaction is EXOTHERMIC with +ΔH

Tags

NGSS.HS-PS3-4

2N₂O₅ --> 4NO₂ + O₂ 
             ΔH_f
N₂O₅    11.289 kJ/mol
NO₂       33.150 kJ/mol
O₂         0 kJ/mol
 ΔHreaction = ?

• 110.022 kJ
• 10.572 kJ
• 121.311 kJ
• 21.861 kJ

Tags

NGSS.HS-PS1-4

An ice cube is placed on a table and begins to melt.  The following conclusion can be made.

• Energy is being absorbed by the table which causes the cube to melt.
• Energy is being transferred from the table to the ice cube.
• Energy is being created by the air and table and making the cube heat up.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A hot object is dropped into a container of cold water. What happens to the molecular motion of the hot object? What happens to the molecular motion of the cold object? 

• the molecules in both objects will slow down until they come to rest
• the molecules of the hot object slow down while the cold speed up
• the molecules of the hot speed up while the cold slows down
• the molecules in both objects will speed up until they reach identical speeds

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4