test Flashcards
why is filtration used
separate an insoluble solid from a liquid
why is crystallisation used
separate soluble solid from a liquid
why simple distillation
sep liquid from solid and keep liquid
explain simple distillation process
-evap liquid by heating + condense vapour by cooling
-condenser has 2 tubes, one inside the other, cold water runs through space between to keep condenser cold
-place solution w/ liquid + dissolved solid in flask connected to a continuous glass + thermometer
-heat solution in flask w/ bunsen burner. evaps +turns to vapor, vapor rises up glass tube, vapour passes into a condenser + condenses bc cold. collect liquid in beaker
why chromatography (paper)
separate substances based on solubility
what is the stationary phase?
paper
what is the mobile phase?
solvent
what is a solvent?
liquid that will dissolve substances
what is the plum pudding model?
atom is a positively charged sphere containing electrons
what did Bohr and Chadwick do
Bohr: electrons orbit the nucleus at specific distances
Chadwick: showed nucleus also contained particles with no charge (neutrons)
how did mendeleev order his table
atomic weight/mass
group 0 trend in bp
bp inc as ram inc (going down)
group 1 + water produces?
hydrogen + hydroxides
group 1 + oxygen/chlorine produces?
solid, white, ionic oxides/chlorides
group 7 trends
-inc bp/mp
-inc molecular mass
-dec reactivity
