AP Chem Unit 4 In Class Review

Which plot corresponds to the lowest temperature?

View the link for a great visual!

https://phet.colorado.edu/sims/html/gas-properties/latest/gas-properties_en.html

• A

• B

• C

• All samples are at the same temperature.

Tags

NGSS.HS-PS3-2

If the two gas samples are put into contact with one another, which of the following best describes the direction of heat flow in order to reach thermal equilibrium?

• From low temperature to high temperature.

• From high temperature to low temperature.

• The samples will NEVER reach thermal equilibrium.

• The samples are already at thermal equilibrium.

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

The specific heat of liquid acetic acid is 2.04 J/g·°C. Calculate the energy released when 100.g of liquid acetic acid is cooled from 61.2°C to 41.2°C.

• 4.08x10³J released

• 2.04x10³J released

• 4.08x10²J released

• 2.04x10²J released

Tags

NGSS.HS-PS3-4

What mass of methane, CH₄, must be burned in a complete combustion reaction to supply 4692 kJ of heat?

CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) ΔH_rxn = −426.5 kJ/mol_rxn

• 176.0 g

• 352.0 g

• 88.0 g

• 427 g

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

The electrolysis of water will generate hydrogen gas, which can then be used in fuel cells, according to the following equation.

2H₂O(l) → 2H₂(g) + O₂(g)

The enthalpy change for the reaction is +570kJ/mol. What is the value of the heat of formation of water?

• +570kJ/mol

• -570kJ/mol

• +285kJ/mol

• -285kJ/mol

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction:

2 CO(g) + O₂(g) → 2 CO₂(g) ΔH = -302.4 kJ/mol

What is the expected energy change for the reaction of three moles of O₂ with four moles of CO?

• -302.4 kJ/mol

• -604.8 kJ/mol

• -907.2 kJ/mol

• -151.2 kJ/mol

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Consider the potential energy diagram shown for the general reaction

reactants → products

and choose the ALL that apply. 

• The reaction represents an endothermic reaction.

• Arrow A represents the enthalpy change for the reaction.

• The reaction absorbs heat energy from the surroundings.

• The reaction releases heat energy to the surroundings.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

During which intervals on the heating curve of water is the average kinetic energy increasing?

NO calculator!

• 1, 2, 3

• 2, 4

• 1, 3, 5

• 1, 2

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

The reaction to describe the combustion of propane is shown below:

C₃H₈(l) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g)   

Using the Lewis structure for propane and table of bond energies provided, what is the enthalpy change for this reaction?

• -2057 kJ

• +2057 kJ

• -3998 kJ

• +3998 kJ

Tags

NGSS.HS-PS1-4

Use the ΔH°_f information provided to calculate ΔH°_rxn..

• -422 kJ
• -62 kJ
• +161 kJ
• +800. kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1