Purity, formulations, chromatography and identification of gases GapFill

Substances which contain only one kind of element or compound are called  cleansolidatomicrefinedpotablepure. They have a specific  densitystrengthvolatilitymelting pointflammabilitytransparency, which is often higher than that of  an unrefineda multiple-compoundan impurea subatomica dirtya blended substance, also known as  a combinationa polymeran alloya mixturean amalgama fusion. In a  fractionblendbrewselectionformulationconcoction such as a cleaning product or a fertiliser, every chemical has a specific purpose and is present in its correct  temperaturepositionquantityqualitypressurestate.

Many mixtures containing coloured compounds can be separated using  polymerisationdistillationtitrationfiltrationcondensationchromatography. During this process, a  constantstationarymotionlesssolidstaticfirm phase, such as paper, is placed in a  liquidvariableflexiblemobilechangeablefluid phase, such as water. The substances travel different  thicknessespathsdistancespatternsspeedsdirections up the paper. Dividing the distance travelled by a substance by the distance travelled by the solvent gives the  pHsolubilityD_s valuepercentageefficiencyR_f value.

When a gas is produced in a reaction, there are many tests which can be used to find out what the gas is. For example:

• a lit splint gives a squeaky pop with hydrogen
• a glowing splint relights in the presence of  oxygenheliumcarbon monoxideneonwater vapourmethane
• carbon dioxide turns  wateracidsmirrorsthe airmetalslime water cloudy
•  iodinenitrogencarbon monoxidechlorinebrominehelium turns litmus paper white