Planet Earth Flashcards
what is decantation
Decantation is a process to separate mixtures by removing a liquid layer that is free of a precipitate, or the solids deposited from a solution.
eg. sand from water
how to determine a saturated solution
remove a drop of solution with glass rod
see whether solids form when drops cool
why cold water is used to wash a crystal after crystallization
remove water-soluble im purities
help reduce loss of salt
principle of simple distillation
water boils at 100.C but salts are non-volatile
steam formed condenses
how to obtain dilute H2SO4 from concentrated H2SO4
concentrated sulphuric acid is added slowly into a large amount of water with constant stirring
what is the function of the glass beads in the fractionating column
to provide a large surface area for condensation and evaporation of the mixture.
daily application of neon
Gas for filling neon lights
outline the underlying principle of simple distillation experiment
Water boils at about 100oC , but the salts in sea water are non-volatile
The steam formed condenses on the cold surface of the condenser to give liquid water.
sodium is….
highly reactive
corrosive
what is quicklime
CaO
Calcium oxide
what is slaked lime
Ca(OH)2
Calcium hydroxide
what is limewater
saturated calcium hydroxide solution
what will thermal decomposition of metal carbonate give out
metal oxide and carbon dioxide
endothermic
is sodium corrosive
yes
as it is alkali metal
is conc. aqeous ammonia corrosive?
yes
as it is concentrated altho it is weak base
fractional distillation of liquid air products
- 183 O2
- 186 Ar
- 196 N2
advantage of using microscale experiment
save cost on chemicals
minimize chemical hazard
reduce chemical waste
what are the sources of CaCO3
marble
limestone
chalk
egg shells
state one natural source of silicon dioxide
sand/quartz
state one industrial use of silicon dioxide
to make glass
using the same amount of reactant, suggest how to increase the volume of liquid collected using the delivery tube and a test tube
immerse the test tube into a ice water bath to enhance the cooling effect
what is relative isotopic mass
relative isotopic mass of an isotope of an element Is the mass of the atom on the C=12 scale
relative isotopic mass= mass of an atom of the element/ (1/12)(mass of an atom of carbon 12)
what is relative atomic mass
relative atomic mass of an element is the average isotopic mass of all natural isotopes on the C=12 scale
Aluminium is the most abundant element in the earth’s crust
T/F
F
its is the most abundant metal > Fe
but < O/N
When distinguishing substance which are solids
Need to do what first
Dissolve the substance in deionised water first
what is saturated solution
a solution containing the maximum amount of solute at a specific temperature
