Chapter 17 Key Concepts Flashcards
How do endothermic processes differ from ectothermic processes?
In an endothermic process, the system gains heat as the surroundings cool down, but in an exothermic process, the system loses heat as the surroundings heat up
In what direction does heat flow between two objects?
From a warmer object to a cooler object
What units are used to measure heat flow?
The calorie and the joule
On what factors does the heat capacity of an object depend?
Both it’s mass and it’s chemical composition
Calorimetry is based on what basic concepts?
The heat released by the system is equal to the heat absorbed by it’s surroundings. The heat absorbed by a system is equal to the heat released by it’s surroundings
How are enthalpy changes treated in chemical equations?
The enthalpy change for the reaction can be written as either a reactant or a product
How does the molar heat of fusion of a substance compare to it’s molar heat of solidification?
The quantity of heat absorbed by a melting solid is exactly the same as the quantity of heat released when the solid solidifies
How does the molar heat of vaporization of a substance compare to it’s molar heat of condensation?
The quantity of heat absorbed by a vaporizing liquid is exactly the same as the quantity of heat released when the vapor condenses
What enthalpy changes occur when a solute dissolves in a solvent?
Heat is either released or absorbed
What are two ways that the heat of reaction can be determined when it cannot be directly measured?
Hess’s law and standard heats formation
