Chemical Analysis Flashcards
What is a pure substance?
Contains only one type of compound/ element
-melts and boils at specific temperatures
What is an impure substance?
Melts & boils over a range of temperatures. Depending on the range of elements
What is a physical test
Test that tests substances physical properties
What is a chemical test?
Test involving Reacting with another chemical
What is an impure substance?
Melts and boils over range of temperatures. Depending on range of elements
What are Formulations?
A mixture that has been prepared using a specific formula, and has a precise amount of different components, as-well as a particular function
(Involves fuel, paint, fertiliser and medicine)
What is a chemical analysis?
Instruments and methods used to separate, identify and quantify different substances
What is paper chromatography (not stages)
Separating dyes in ink
What are the steps of paper chromatography?
Steps: 1 get filter paper and add a baseline and ink sample to the paper. Then filter the beaker with solvent
Steps 2: place filter paper into solvent, but not submerging Basilian’s into it, and placing lid on top
Step 3: the solvent seeps up paper forming different dyes(hence different substances)
Step 4: once it was seeped up to the top of the paper, take the paper out to dry. Leaving a chromatogram to form
What is the mobile phase?
When molecules can move(solvent/liquid/gas) is more soluble
What is the stationary phase?
When molecules can’t move (solid, paper) is less soluble
Why is a lid needed on the beaker in a chromatography test?
To stop solvent evaporating
What is the chromatography test dependent on?
. The properties of a substance
What is the Rf value?
Distance travelled by substance
_________________________________
Distance travelled by solvent
How do you test for chlorine(chlorine test)
Place blue, damp litmus paper into a test tube full of sample Gas.
If chlorine is present, then the litmus paper will turn red then white
Why does the litmus paper turn red?
The chlorine will dissolve in the water to form Hydrochloric acid
What should you wear when performing chlorine gas?
Wear a mask
How do you test for oxygen?
Place glowing splint into tube of sample gas. If it relights then oxygen is present(as oxygen is needed to make fire)
How do you test hydrogen?
Move burning splint close to sample gas, if it make a squeaky pop sound, the hydrogen is present
How do you test for carbon dioxide?
Connect a glass with sample gas via a tube to another glass heater with calcium hydroxide
If the calcium hydroxide bubbles, causing the solution to get cloudy, mean carbon dioxide is present in the sample glass tube