Physics: Equations, Eponymous Laws and SI Units Flashcards
Boyle’s Law
P∝1/V i.e. P1V1 = P2V2
Pressure is inversely proportional to volume
Charles’ Law
V∝T i.e. V1/T1 = T2/V2
Volume is proportional to temperature
Gay-Lussac Law
P∝T i.e. P1/T1 = P2/T2
Pressure is proportional to temperature
Avogadro’s Law
Equal volumes of all gases, at the same temperature and pressure, have the same number of molecules
i.e. V ∝ n
Molar Volume
22.41 litres/mol at standard temperature and pressure (273.15K i.e. 0°C and 101.325kPa i.e. 1 atm)
Ideal Gas Equation
PV = nRT, where R is the Boltzmann constant
Henry’s Law
At constant pressure, amount of gas dissolved in a solvent is proportional to the partial pressure above the solvent
Dalton’s Law
The partial pressure of a fixed mass of gas in a mixture of gasses is the same as the pressure it would exert alone
Hysteresis
The dependence of the state of a system on its history i.e. a measurement differs depending on whether the value is rising or falling.
SI unit of time
Second (s) - one second = 9,192,631,770 oscillations of a Caesium-133 atomic clock.
SI unit of distance
Metre (m) - One metre = The distance travelled by light in vacuum in 1/299,792,458 second
SI unit of amount of substance
Mole (mol) - One Mole = The amount of substance containing the same number of atoms/molecules as there are atoms in 12g of Carbon-12
SI unit of current
Ampere (A) - One Ampere = The current applied to two parallel conductors of negligible cross section and infinite length, one metre apart in a vacuum which would produce a force between them of 2.0 x 10-7 Newtons per metre.
SI measure of luminous intensity
Candela (cd) - One Candela = The luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 5.4×1014 Hertz and that has a radiant intensity in that direction of 1/683 watt per square radian
SI measure of mass
Kilogram (kg) - One Kilogram = The mass of the international kilogram prototype in Pavillon de Breteuil, Sévres, France.
SI measure of temperature
Kelvin (K) - One Kelvin = 1/273.16 of the thermal energy of the triple point of water.
Heat - definition
Type of energy that moves between two objects due to a difference in temperature
Temperature - definition
A measurement of the average kinetic energy of a particles in a system.
OR
Property of an object which determines if heat energy will flow to or from it from another object
Absolute zero
Absolute zero is defined as the temperature at which all molecular movement stops
Specific heat capacity
The amount of heat energy required to increase one Kg of a substance by one Degree Centigrade/Kelvin
Beer’s Law
The absorption of radiation as it passes through a substance increases exponentially as the concentration of the substance increases
Lambert’s Law
The absorption of radiation as it passes through a substance increases exponentially as the distance it travels through the substance increases
Beer-Lambert Law
Intensity of emergent light = Intensity of incident light x e^-(Distance light travel through substance x concentration of substance x ε - molar absorption coefficient)
I = Io x e^-DCε
