C8 Flashcards
What is a formulation
examples
A mixture that has been designed as a useful product
paint, alloys, furitiliser
What is the test and result for hydrogen
gas?
Test: add BURNING splint to the gas
Result: burns with a squeaky pop
What is the test for oxygen?
Test: add GLOWING splint to the gas
Result: splint relights
What is the test and result for carbon
dioxide gas?
Test: bubble gas into limewater
Result: limewater turns cloudy
What is the test and result for chlorine gas?
Test: add damp blue litmus paper
Result: litmus paper bleaches and turns white
What is a pure substance? What are it’s properties?
-A single element or compound, not mixed with any other substance
-Hasn’t been mixed with anthing else
-1 specific melting and boiling point
-Has only 1 spot in chromatoghaphy
How can you test the purity of a substance
Measure its melting or boiling point. Impure substances have different melting and boiling points.
In chromatography, what is the stationary
phase
Chromatography paper
In chromatography, what is the mobile
phase
The solvent (e.g. water)
Which dye moves furthest up the paper
The most soluble
What is the equation for Rf value?
Rf=distance moved by substance/distance moved by solvent
distance moved by solvent measured by/in middle of dye
What should you remember to do in the
chromatography practical?
1.Draw start line in pencil
2.Make sure solvent level is below the start line
How can you test if a substance is pure in
chromatography.
A pure substance gives a single spot in all solvents.
What is the colour of the flame produced from lithium?
Crimson
What is the colour of the flame produced from
a COPPER containing compound?
Green
What is the colour of the flame produced from
a SODIUM containing compound?
Yellow
What is the colour of the flame produced from
a POTASSIUM containing compound?
Lilac
What is the colour of the flame produced from
a CALCIUM containing compound?
Orange-red
Which solutions produce white precipitates
with sodium hydroxide?
Solutions containing aluminium, magnesium or calcium ions
How can aluminium ions be distinguished from
calcium and magnesium ions?
Its precipitate will dissolve in excess sodium hydroxide
What colour precipitate forms from adding
sodium hydroxide to copper (II) ions?
Blue
What colour precipitate forms from adding
sodium hydroxide to iron (II) ions?
Green
What colour precipitate forms from adding
sodium hydroxide to iron (III) ions?
Brown
What is the test for carbonate ions?
Add hydrochloric acid, test gas formed with limewater
What is the test for halide ions?
Add silver nitrate and nitric acid to generate a silver halide precipitate
What colour are the halide precipitates?
chloride=white,
bromide=cream,
iodide=yellow
Chickens Be Idiots
What is the test for sulfate ions?
Add barium chloride and hydrochloric acid, forms white precipitate
What instrumental method can be used to test
for metal ions?
Flame emission spectroscopy
What is the perpous of chromatogrphy?
Seperate mixtures based on their solubility to identify subsances
What is the moblie phase in chromatoghraphy?
when subsance is moving up paper
Decribe the method for chromatoghraphy
- Draw line in pencil ( so line doesn’t run into the inks)
- Add spots of unknow and known colour on the line
- Place chromatography paper in beacker with solvent, below pencil line
- Leave paper untill solvent has reached the top
- Remove paper, leave solvent to dry
- Compaire postions of known and unknown colours.
