Ideal Gases

Ideal GasesBy :Alocitta .A /01Aulia Shalmaa P.R /05Rizandi Arya P / 20Mariera Anisa /26M. Iqbal H /27Robert BrownThe movement of gas particle was investigated as long ago as the 1820s by Robert Brown (english botanist). He was investigating the motion of pollen grains

Explaining PressureA gas exerts pressure on any surface with which it comes into contact. Pressure is a macroscopic property, defined as the force exerted per unit area of the surface (F/A).Pressure of the atmosphere at sea level is axp 105 PaThe gas laws and absolute zeroTherere 4 properties of this gas that we might measure :Pressure, temperature, volume, and mass

One mole of any substance is equal to relative molecular mass of the substance measured in gramsBoyles Law

We can represent boyles law as a graph (beside). A graph of p against 1/V is a straight line passing through the origin, showing direct proportianality*M & T remain constantCharless law

Charless law describes how the volume of a gas depends on its tempetature.*M & T remain constantThe volume of a fixed mass of a gas is directly proportional to its absolute temperature, provided its pressure remains constantThe Pressure Law

This law describes how the pressure of a gas changes as the temperature changes

The Thermodynamic (kelvin) ScaleWe use different symbols to represent temperatures on these two scales : for the Celcius scale, and T for the thermodynamic (Kelvin) scale. Relationships to convert between the two scales (oC) = T(K) 273T (K) = (oC) + 273

----- Meeting Notes (5/19/13 19:06) -----The thermodynamic scale is sometimes known as the Kelvin scale temperature. It does not depend on somewhat variable of substances (melting & boiling point)

8Ideal Gases EquationpV = nRT

The general equation for ideal gases can also be expressed in terms of mass (in kg). It can be obtained by substituting n=m/MpV = (m/M)RTThe general equation for ideal gases can also be expressed in terms of density of a gas (kg/m3).= m/V = pM/RT The general equation for ideal gases can also be expressed in terms of the number of gas particles, N.N =nNA or n=N/NA (NA = 6,022 x 1028 mole/kmole)

If the value of n is substituted into the first equation of ideal gas we can get

pV = NkT

Which K is called the Boltzmann constant and it equals to R/NA = 8134 J/kmole K 6,022 x 1028 mole/kmoleTemperature and molecular energyThe equation of state for an ideal gas relates four macroscopic properties of a gas pressure, volume, temperature and amount of a gas.