Week 16.1 - 1st Law of Thermodynamics

What is kinetic energy?

energy associated with movement

Formula kinetic energy

Ek=1/2 mv2

What is m in the formula and its SI

mass - Kg

What is v in the formula and its SI

velocity s/m

What is potential energy?

energy possessed due to position

Formula of potential energy

Ep= mgh

What is g in the formula and its SI

gravity - 9.81 ms-2

What is h in the formula and its SI

height - m

Formula of total energy E

E= Ek + Ep

Law of conservation of energy

Energy can neither be created or destroyed

Types of system

open, closed and isolated

What happens when the system is open?

exchange ENERGY and MATTER with surroundings

What happens when the system is open?

exchange ENERGY with surroundings

What happens when the system is open?

exchange NEITHER ENERGY NOR MATTER with surroundings

Exothermic

release heat into the surroundings

What type of reaction are combustions?

exothermic

Endothermic

absorb heat from the surroundings

What is the symbol of heat?

q

What is the symbol of work?

w

What is the symbol of volume?

V

What is the symbol of change in

triangle

What is the symbol of area?

A

What is the formula of work?

\-pexΔV

What is the symbol of external pressure?

pex

What is the formula of work?

\-nRT ln(Vf/Vi)

What is Vi?

initial volume

What is Vf?

final volume

What is T?

Temperature

What is R?

Universal gas constant

What is the symbol of heat capacity?

C

What is Cs and its SI unit?

specific heat capacity J K-1 g-1

What is Cm and its SI unit?

Molar heat capacity J K-1 mol-1

What is Cp?

Heat capacity at constant pressure

What is Cv?

Heat capacity at constant volume

Heat capacity formula

C= q/ΔT

transferred heat (q)

q= CΔT

Moral internal energy symbol

Um

Changes internal energy symbol

ΔU

Changes internal energy formula

ΔU= w+q

1st law of thermodynamic

Isolated systems can neither do work or heat surroundings. Their internal energies can not change, it’s constant

At constant pressure, q=

ΔH