Matter Part 1 (copy)

what is an aerosol

dispersion of a solid or liquid in a gas

what does a nebuliser do

converts a solution of a drug into an aerosol for inhalation

what are the different types of aerosols

MDI, nebliser or DPI

Metered dose inhaler facts (4)

• most common

• aerosol created when valve is opened

• drug usually contained in small particles suspened in liquid propellant

nebuliser facts 2

• oldest

• uses drug contained in a solution

dry power inhaler facts 5

• aerosol is a powder until inhaled

• intended to be left in the device or in the mouth - throat

• They add large particles of lactose monohydrate

how does a liquefied gas aerosol work 3

• an equilibrium is established between the liquefied propellant and its vapour

• when the valve is opened the pressure forces some liquid out of the dip tube and out into the atmosphere

• aerosol propellant vaporises and disperse the active ingredient

liquified gas aerosol picture

what happens to vapour pressure in the liquefied gas aerosol

the vapour pressure therefore will remain constant

what do hydrofluroalkanes do (HFAs)

produce aerosols

whats a benefit of using HFAs over CFCs

HFAs do not destroy ozone layer

what are the two most common HFAs

tetrafluoroethane (HFA 134a) and heptafluoropropane (HFA 227)

what does a compressed gas aerosol contain

compressed gas and a solvent

what is the molar enthalpy of vaporisation

the quantity of heat absorbed when 1 mole of a liquid vaporises at the normal boiling point

In a compressed gas aerosol, indicate how the vapour pressure above the aerosol mixture will change during useage.

it will decrease

entonox gas is made up of what

50 : 50 mixture of nitrous oxide and oxygen

what is charles law

if the temperature increases then the volume increases proportionally.

what effect does increasing the temperature of a liquid have on its vapour pressure.

vapour pressure increases

Formulae you should know:

P_Total=P^O_A X_A +P^O_B X_B

P₁V₁= P₂V₂

(P₁V₁)/T₁= (P₂V₂)/T₂