Test 4 Flashcards
Which contains more energy: 25g of boiling water at 100°C or 25g of steam at 100°C?
25g of steam at 100°C
What statement best explains the fact that the change in internal energy(delta E) equals the difference of the final value and the initial value?
Internal energy is a state function
What term refers to the randomness of a substance or system?
Entropy
What is the internal energy of a system plus the product of its pressure and volume?
Enthalpy
What statement describes what happens when water at 0°C changes to ice at 0°C?
Heat is released
Describe ether flow of heat
Heat flows from higher temperature to lower temperature
Define energy
The ability to work
What device is used to measure heat flow during physical processes or chemical reactions?
Calorimeter
What changes would be expected to increase entropy?
Acetone evaporation
Dye diffusing in water
Sodium chloride dissolving in water
What law states that the change in a system’s internal energy is the sum of the heat added to the system and the work done on the system?
First
The thermodynamic state of a substance I it’s normal physical state at 1 atm and 298 K is the substance’s_____?
Standard state
What process are chemical and physical changes that release heat?
Exothermic
When discussing thermodynamic concept, what is the portion of the universe or the sample of matter under study?
What is everything else called?
System
Surroundings
What is the SI unit of energy, whether heat or work?
Joule
What is the field of chemistry that deals with the energy changes in chemical reactions?
Thermodynamics
What process are chemical reactions and physical changes that absorb heat?
Endothermic
What type of energy is associated with position relative to a force?
Potential energy
An endothermic reaction is characterized by what type of change in enthalpy?
Positive
What is the entropy of the universe, according to the second law of thermodynamics?
Increasing
What is the enthalpy of formation for any element in its standard state?
Zero
When a cup of water evaporates into water vapor, the entropy change of the system is_____?
Positive
At cinstant pressure, enthalpy change equals what?
Heat
The heat per unit mass required to vaporize a substance at its normal boiling point
Heat of vaporization
The total amount of heat liberated or absorbed because of a chemical reaction
Heat of reaction
