Chapter 6.1 Forms of Energy and Their Interconversion

Question 1

system

Answer 1

the part of the universe we are focusing on

Question 2

surroundings

Answer 2

everything else other than the system

Question 3

internal energy (E)

Answer 3

the sum of both potential energy and kinetic energy of a system

Question 4

ΔE definition

Answer 4

the difference between the internal energy AFTER the change (Efinal) and BEFORE the change (Einitial)

Question 5

ΔE equation

Answer 5

ΔE = Efinal - Einitial = Eproducts - Ereactants

Question 6

What happens when the Energy of system DECREASES

Answer 6

system releases some energy in a transfer TO the surroundings:
Efinal

Question 7

What happens when the Energy of system INCREASES

Answer 7

system absorbs some energy in a transfer FROM the surroundings:
Efinal > Einitial so ΔE > 0

Question 8

Heat (thermal energy) [q]

Answer 8

the energy transferred as a result of a difference in temperature between the system and the surroundings

Question 9

Work (w)

Answer 9

the energy transferred when an object is moved by a force

Question 10

Equation for the total change in a system’s internal energy

Answer 10

ΔE = q + w

Question 11

What happens when work is done BY a system

Answer 11

system releases energy as work, so w is negative:

Efinal

Question 12

What happens when work is done ON a system

Answer 12

energy is transferred as work done BY the surroundings ON the system, so w is positive:
Efinal > Einitial, so ΔE is positive

Question 13

Law of Conservation of Energy

Answer 13

energy is conserved: the total energy of a system + the surroundings remains constant

Question 14

1st Law of Thermodynamics

Answer 14

the total energy of the universe is constant:

ΔEuniverse = ΔEsystem + ΔEsurroundings = 0

Question 15

Units of Energy

Answer 15

1J = 1kg · m/s²

Question 16

Equation to find w

Answer 16

work = force x distance
w = f x d

Question 17

force

Answer 17

changes the velocity of a mass over time; a force accelerates a mass
mass(m, in kilograms) times acceleration

Question 18

velocity

Answer 18

meters per second per second (m/s² )

Question 19

Calorie (cal)

Answer 19

the quantity of energy needed to raise the temperatuer of 1g of water by 1°C

Question 20

Units for Calorie

Answer 20

1cal = 4.184 J   OR 1J = 1/4.184 cal = 0.2390 cal
1kJ = 1000J = 0.2390kcal = 239.0 cal

Question 21

British Thermal Unit (Btu)

Answer 21

quantity of energy required to raise the temperature of 1lb of water by 1°F:
1 Btu = 1055J

Question 22

state function

Answer 22

internal energy (E) of a system dependent only on the CURRENT state of the system

Question 23

path independence

Answer 23

changes in state functions (ΔE, ΔP, ΔV, and ΔT) depends only on the initial and final states