Chemical Analyis Flashcards
What does the word pure mean ?
Just one substance, only one element
What is a mixture ?
Two substances mixed together not chemically combined
What’s an example of a mixture of elements and compounds ?
The air
What are 3 examples of formulations ?
Fuel
Paint
Medicines
What is the line drawn in at chromatography ?
Pencil line
What do the dots have to be in ?
Ink so it travels up the paper
Why do different colours occur in the chromatography ?
The substances move at different speeds through the paper allowing you to see all the colours in the ink
How do you calculate RF value ?
Distance travelled by substance / Distance travelled by solvent
What’s the solvent and solution usually in chromatography ?
Solution is water
Solvent is ink
What is the method for the chromatography test ?
- draw a pencil line across the chromatography paper, 1 - 2 cm from the bottom
- use a pipette or capillary tube to add small spots of each ink to the line on the paper
- place the paper into a container with a suitable solvent in the bottom
- allow the solvent to move through the paper, but remove the chromatogram before it reaches the top
- allow the chromatogram to dry, then measure the distance travelled by each spot and by the solvent
What can we do to prevent hazards and injuries happening ?
Wear goggles
Be sure of the solvent you are using
What is the test for oxygen ?
If oxygen is present in a test tube, a glowing splint relights when it is held inside.
What is the test for hydrogen ?
If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop.
What is the test for carbon dioxide ?
If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white.
What is the test for chlorine ?
If damp blue litmus paper is used, the paper turns red then white.
