Chapter 5.2 The first Law of Thermodynamics

Question 1

THE FIRST LAW OF THERMODYNAMICS

Answer 1

. Energy is neither created or destroyed
. Energy that is lost by a system must b gained by its surroundings (vice versa)
. Energy is conserved
Energy is constant

Question 2

INTERNAL ENERGY

Answer 2

E = is the sum of all the kinetic and potential energies of the component of a system

Question 3

” DELTA” E

Answer 3

the change in internal energy

Question 4

3 parts to a thermodynamic number such as “ delta “ E

Answer 4

1. a number
2. a unit
   together give the magnitude of change
3. a sign that gives the direction (
   . a positive value of

Question 5

In a chemical reaction what is the initial state of the system and what is the final state

Answer 5

The reactants= initial state

The product=the final state

Question 6

The 2 general ways that a system can exchange heat with its surroundings (contributing to a change in internal energy

Answer 6

1. heat ( added or removed)

2. work ( done on or by the system)

Question 7

When a system undergoes a chemical reaction the formula for the change in internal energy,

Question 8

2 terms to indicate the direction of the transfer of energy

Answer 8

1. Endothermic

2. Exothermic

Question 9

ENDOTHERMIC

Answer 9

When a process occurs in which the system absorbs heat
. heat is transferred into the system from its surroundings
e.g. the melting of ice

Question 10

EXOTHERMIC

Answer 10

A process in which a system loses heat to its surroundings

. eg combustion,heat exist or flows out of a system into the surroundings.

Question 11

The 2 conditions that influence internal energy

Answer 11

1. Temperature

2. Pressure

Question 12

What type of property is energy

Answer 12

Extensive Property

Question 13

What are the conditions that influence internal energy

Answer 13

1. temperature
2. pressure
3. the quantity of matter in the system

Question 14

STATE FUNCTION

Answer 14

a property of a system that is determined by specifying the system’s condition or state( in term of temp, pressure etc)

The VALUE of a state function DEPENDS ONLY on the PRESENT STATE OF the system, not on the path the system took to reach the state.

eg. Driving from chicago which is 596ft to denver which is 5280 ft. The change / difference in altitude is still the same regardless of the distance or the path to get there ( the altitude is the state function, the distance is not.

Question 15

eg of a STATE FUNCTION

Question 16

q + W are not state functions why?

Answer 16

because they depend the way in which the change occurs ( similar to the different route choice and distances from