Chemistry - Topic 8 Chemical analysis Flashcards
What is a pure substance?
A pure substance is a single element or compound not mixed with any other substance.
What is formulation?
Formulation is a mixture that has been designed as a useful product.
Give three examples of formulations.
Hair dye
Concrete
Ink
How would the boiling point of impure copper sulfate be different from that of pure copper sulfate?
Pure copper sulfate has a sharp boiling point at a single temperature. Impure copper sulfate would boil over a wider temperature.
What is Chromatography?
It is a technique for the separation of a mixture by passing it through a solution or suspension through a medium in which the components move at different rates.
How do you calculate Rf values?
Rf=distance travelled by substance/distance travelled by solvent
Give three examples of pure substances?
Diamond, Oxygen, Glucose
What is the boiling and melting point of water?
Boiling point: 100 degrees Celcius
Melting point: 0 degrees celcius
How do you test for oxygen?
You insert a glowing splint (one that has been just blown out) into a tube of the gas, if the splint relights then there is oxygen present.
How do you test for hydrogen?
Insert a burning splint into a tube of the gas. If there is a sqeaky pop sound, hydrogen is present
How do you test for CO2?
The gas is shaken with or bubbled through limewater, if the Limewater goes milky CO2 is present.
How do you test for Chlorine?
Insert damp (red or blue) litmus paper into the gas, if the litmus paper is bleached, which means to turn white, chlorine is present.
