Chapter 5 key terms Flashcards
(21 cards)
What is electrostatic potential energy?
the amount of work done to move a unit charge from a reference point to a specific point inside the field without producing an acceleration
When does electrostatic occur?
seen between oppositely charged ions
Is energy released or consumed when chemical bonds are formed?
released
What is the relationship between potential energy and the distance of ions from one another?
As Ions become closer, potential energy decreases
Is energy consumed or released when chemical bonds are broken?
consumed
What is an open system?
a region that can exchange heat and mass with its surroundings
What is a closed system?
a region that can only exchange heat with its surroundings
What is an Isolated system?
a region that can’t exchange heat or mass with its surroundings
Is delta E positive or negative when the system gains energy from the surroundings?
positive
Is delta E positive or negative when the system loses energy to the surroundings?
negative
Meaning of +q and - q
+q: system gains heat
-q: system loses heat
Meaning of +w and -w
+w: work done on the system
-w: work done by system
meaning of +deltaE and -deltaE
+deltaE: net gain of energy by system
-deltaE: net loss of energy by system
What’s an endothermic process?
heat is absorbed by the system from the surroundings
What’s an exothermic process?
heat is released by the system into the surroundings
At constant pressure what is enthalpy?
the heat gained or lost
Is deltaH positive or negative in an endothermic process?
positive
Is deltaH positive or negative in an exothermic process?
negative
What does enthalpy change for a reaction depend on?
the states of the reactants and the products
What is bond enthalpy?
the enthalpy associated with breaking one mole of a particular bond in a gaseous substance
Can bond enthalpy be negative?
No, its always positive because energy is required to break chemical bonds
