Enthalpy Vocabulary

What does the enthalpy of combustion measure?

• The volume of gas produced when a substance burns

• The change in pressure when a substance burns

• The light emitted when one mole of a substance burns completely in oxygen

• The heat released when one mole of a substance burns completely in oxygen

Tags

NGSS.HS-PS1-4

ΔH value in an endothermic reaction is a positive number.

• True

• False

Tags

NGSS.HS-PS1-4

Based upon the graph above, what type of reaction is this?

• Endothermic

• Exothermic

Tags

NGSS.HS-PS1-4

What is the standard enthalpy change of formation?

• The enthalpy change when one mole of a compound is formed from its elements in their standard states.

• The enthalpy change when one mole of a compound is dissolved in water.

• The enthalpy change when one mole of a compound is burned in oxygen.

• The enthalpy change when one mole of a compound is vaporized.

Which of the following is true about enthalpy?

• Enthalpy is a measure of the disorder of a system.

• Enthalpy is a measure of the energy stored in chemical bonds.

• Enthalpy is a measure of the temperature of a system.

• Enthalpy is a measure of the volume of a system.

In an exothermic reaction, the enthalpy of the products is:

• Greater than the enthalpy of the reactants.

• Less than the enthalpy of the reactants.

• Equal to the enthalpy of the reactants.

• Unrelated to the enthalpy of the reactants.

Tags

NGSS.HS-PS3-1

What does Hess's Law state about enthalpy?

• The enthalpy change of a reaction depends on the pathway taken.

• The enthalpy change of a reaction is independent of the pathway taken.

• The enthalpy change of a reaction is always positive.

• The enthalpy change of a reaction is always negative.

Which of the following processes has a positive enthalpy change?

• Combustion of methane.

• Freezing of water.

• Melting of ice.

• Condensation of steam.

What is the unit of enthalpy in the International System of Units (SI)?

• Joule (J)

• Calorie (cal)

• Watt (W)

• Pascal (Pa)

How is enthalpy change represented in a chemical equation?