mod 3 Flashcards
what is the formula for decomposition reaction?
chemical A –> chemical B + chemical C
what is decomposition reaction?
one substance changes into two (or more) chemical subtances
what can a decomposition reaction be caused by?
- heat (thermolysis)
- electricity (electrolysis)
- light (photolysis)
what is a combustion reaction?
a chemical substance (fuel) reacts rapidly with oxygen to release energy
what is the formula for combustion reaction?
fuel + oxygen –> carbon dioxide + water
what is needed to start combustion?
- a spark
what is a synthesis reaction?
two (or more) chemical substances react to make one (main, complex) substance
what is the formula for a synthesis reaction?
chemical A + chemical B –> chemical C
what is a precipitation reaction?
two soluble ionic compounds in solution are combined and react to produce a new ionic compound that is insoluble
what happens to the insoluble compound after a precipitation reaction?
the insoluble compound makes the mixture cloudy and eventually ‘falls’ to the bottom which is called the precipitate
what is the formula for a precipitation reaction?
AB(aq) + CD(aq) –> AD(s) + CB(aq)
what are the solubility rules?
- ammonium
- group 1 metals
- nitrate
- acetate
- chlorine, bromine, iodine
- sulfate
what are exceptions to the solubility rules?
- group 1 metals: Li3PO4 (lithium phosphate) is insoluble
- acetate: Fe(CH3COO)3 is slightly soluble and AgCh3COO is slightly soluble
- chlorine, bromine, iodine: AgCl, AgBr, AgI and PbI2 are insoluble and PbCl2, PbBr2 are slightly soluble
- sulfate: BaSO4, PbSO4 are insolube & CaSo4, Ag2SO4 are slightly soluble
what are the insolubility rules?
- hydroxide
- carbonate
- phosphate
what are exceptions to the insolubility rules?
- hydroxide: group 1 salts, ammonium & Ba2+ / Ca(OH)2 and Sr(OH)2 are partially soluble
- all carbonates, phosphates and sulfide: group 1 and ammonium
what is complete combustion?
occurs when there’s excess oxygen present
what is incomplete combustion?
occurs when there’s and insufficient supply of oxygen
what is the formula for acid and reactive metals reactions?
acid + reactive metal –> salt + hydrogen
what is the formula for acid and base (neutralisation) reactions?
acid + base –> salt + water
what is the formula for acid and carbonate reactions?
acid + carbonate –> salt + carbon dioxide + water
how do Aboriginals and Torres Strait Islander people remove toxins from their food?
- three ways to remove cycasin toxin
- brief leaching
- prolonged leaching
- aging & fermentation
what is brief leaching?
cooked to denature toxin (less harmful) –> crushed to increase surface area –> leached overnight = placed in bags in a running stream (soluble toxin removed) –> eaten
what is prolonged leaching?
crushed to increase surface area –> leached over 3-9 = placed in bags in a running stream (soluble toxin removed) –> cooked to denature toxin –> eaten
what is aging and fermentation?
seeds buried under cycad plant in moist soil –> anaerobic micro-organisms act on seeds over weeks –> fermentation produces alcohol dissolves toxin into soil –> removed –> eaten