C8: Chemical Analysis Flashcards
What is a pure substance?
Consists of a single element or comping, no other substances
What is a mixture?
2 elements no chemically combined
What is the difference between the boiling point of our and impure liquids?
Pure- specific and sharp boiling point
Impure- range of boiling points
What is a formulation?
A mixture that has been designed as a useful product
What is chromatography?
A method for separating a mixture of coloured solutes in a dye
What is solubility?
The measure of how well a solute dissolves in a solvent
Chromatography process
1) set up the chromatography paper upright in a beaker with a line drawn in pencil and different inks
2)fill water just until it touches below the line
3) wait until the inks travel up the paper, the one that travels highest has the highest solubility
What is the mobile phase in chromatography?
Solvent
What is the stationary phase in chromatography?
Chromatogramme (paper)
What will a pure substance produce on a chromatogram?
One spot only
What will a mixture produce on a chromatogram?
Different spots
Rf value calculation?
Distance travelled by spot / distance travelled by solvent
What is the test for hydrogen?
Holding a burning splint at the open end of the test tube, it present, there will be a squeaky pop (result of rapid combustion)
What is the test for oxygen
Placing a glowing splint inside the test tube of gas , if present the splint will relight
What is the test for carbon dioxide?
Bubbling the gas through limewater (calcium hydroxide), if present it will turn milky or cloudy
What is the test for chlorine?
Use of litmus paper, if present the blue paper will turn red then bleached white
