Sci- testing, mixing and separating Flashcards
What is a compound (give examples)
A compound is any substance that has 2 or more elements chemically joined together in a fixed ratio.
Eg. Water H20, salt NaCl, sugar C12H22011
what is a mixture
a matreial made up of 2 or more substances that are physically combined. Individual substances retain their own proporties
eg air
What is a chemical formula
A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
eg water
Dissolve
The process of mixing the solute with the solvent to get a clear solution.
Dilute
few particles of a solute are present in a given volume of solvent
concentrated
lots of particles of a solute are present in a given volume of solvent
saturated
no more solute can dissolve in the solvent
solute
the substance that you dissolve
solvent
the liquid that you dissolve substances in
solution
the mixture formed when you dissolve a solute into a solvent
Soluble
able to be dissolved in a solvent
insoluble
unable to be dissolved in a solvent
what is CO2
carbon dioxide
what is MgCI2
Magnesium chloride
what is CaCI2
calcium chloride
2 proporties of carbon dioxide gas
odorless and colourless
what is the word equation for producing hydrogen gas in the lab + the name of the test for it
hydrochloric acid+magnesium—–> magnesium chloride +hydrogen gas
pop test
word equation for carbon dioxide +test for it
calcium carbonate+nitric acid—–> calcium nitrate+carbon dioxide+water
lime water test
word equation for oxygen + test for it
hydrogen peroxide—- manganese dioxide–> water
glowing splint test
how many times should you repeat a test to calculate a fair average
3
what is filtration
filtration seperates solble particles from insoluble particles in a solvent. If you have a mixture of two solids you can add water to dissolve one, filter off the insoluble one and then evaporate the water from the dissolved solid to recrystallize the soluble solvent.
what is evaporation
To remove a solute that is dissolved in a solvent you can use evaporation. The solution is poured into an evaporating dish and heated. The solvent forms a gas and evaporates, leaving the solute as a solid in the dish.
what is distillation
if you want to collect the solvent as well as the solid or if you have two different liquids, then you should use distillation. It separates substances on the basis of their boiling points
LOOK OVER SEPERATING THING
DO IT
Positive test for hydrogen
You will hear a loud squeaky pop.
positive test for carbon dioxide
liquid turns a milky colour
positive test for oxygen
the splint relights, often many times
what is the correct symbol for sodium hydroxide
S(H)2
what is a mixture with excess solute is called
saturated solution
what seperates liquids
chromotography
