Lesson 1 - Introduction to thermochemistry

Question 1

Thermodynamics

Answer 1

Study of energy and energy transfer

Question 2

Thermochemistry

Answer 2

Study of changes in the energy content of matter associated with chemical reactions and phase changes

Question 3

Kinetic Energy

Answer 3

Energy of movement

Question 4

Potential Energy and say the two types

Answer 4

Energy of condition, stored to be used as kinetic energy. Chemical potential (chemical bonds) and Gravitational potential (energy due to elevation)

Question 5

Name the 3 types of systems

Answer 5

Open system, Closed system, Isolated system

Question 6

Open System and say example

Answer 6

Exchanges both energy and matter
Ex.) Heating water on a stovetop

Question 7

Closed System and say example

Answer 7

Exchanges only energy and not matter
Ex.) Heating water on a stovetop with a closed lid

Question 8

Isolated System and say example

Answer 8

Cannot exchange energy or matter
Ex.) Heating water on a stovetop in a closed vessel, like a thermos or cooler

Question 9

System

Answer 9

Any sample under observation

Question 10

Surroundings

Answer 10

Everything that is not a part of the system

Question 11

Thermal Energy

Answer 11

The sum of all the kinetic energies of all the particles in a system (this is immesurable)

Question 12

Temperature

Answer 12

Average Kinetic energy of all the particles in a system

Question 13

Units to measure temperature

Answer 13

Celsius and Kelvin
Temperature (K) = Temperature (C) + 273.15

Question 14

Specific Heat Capacity (c)

Answer 14

Amount of energy needed to raise a temperature of 1 gram of a specific substance by 1 degree celsius

Question 15

SATP

Answer 15

Standard Ambient Temperature and Pressure

Question 16

Equation of Q

Answer 16

Q=mcΔT

Question 17

What is the first law of thermodynamics?

Answer 17

Energy must be conserved; it is neither created nor destroyed. Therefore, the energy of the universe is constant

Question 18

ΔEUniverse =

Answer 18

ΔEUniverse = ΔEsystem + ΔEsurroundings = 0

Question 19

ΔEsystem =

Answer 19

ΔEsystem = -ΔEsurroundings

Question 20

What is the second law of thermodynamics?

Answer 20

When 2 objects are in thermal contact, heat transfers from high to low temperature until the two objects are at the same temperature

Question 21

Enthalpy

Answer 21

Total enegy of the system plus pressure times volume

Question 22

ΔH=

Answer 22

ΔH = ΔE + Δ(PV)

Question 23

Why is enthalpy a state function?

Answer 23

Enthalpy only examines the change a system underwent, NOT the path taken to get there

Question 24

For solid and liquid reactions in an open system…

Answer 24

It can be assured that there is no change in pressure or volume so ΔPV = 0, meaning that Q = ΔE = ΔH

Question 25

Endothermic reactions

Answer 25

Heat enters a system during a process, thus enthalpy is positive

Question 26

Exothermic reactions

Answer 26

Heat leaves a system during a process, thus enthalpy is negative