chemical analysis Flashcards
(22 cards)
what is a pure substance?
one that is made up of one substance - can be element or compound
what is an example of a formulation?
medical drugs - often only contain 5-10% of the active drug
what is a formulation?
a mixture that has been designed to produce a useful product
what is the test for hydrogen?
squeaky pop test
what is the test for carbon dioxide?
bubble gas through lime water and observe colour change- cloudy
what is the test for oxygen?
relight a glowing splint
what do equal volumes of gases at the same temp and pressure have in common?
contain the same number of molecules
what is the flame test colour for lithium?
crimson
what is the flame test colour for sodium?
yellow
what is the flame test colour for potassium?
lilac
what is the flame test colour for calcium?
orange-red
what is the flame test colour for copper?
green
what can help you identify some positive ions?
reacting unknown compounds with sodium hydroxide solution
what happens if there is a mixture of metal ions?
some flame colours can be masked
what is a qualitative chemical test?
one that relies upon subjective observation
what is a quantitative chemical test?
one that relies upon making/taking measurements
what are the advantages of instrumental analysis? (3)
very accurate
reliable
fast
why is flame emission spectroscopy used?
it can detect individual wave lengths
what is the test for sulfates?
add dilute hydrochloric acid and barium chloride together, if a white precipitate is formed = positive for sulfate
what is the test for halides?
add dilute nitric acid and silver nitrate together, if a precipitate is formed = positive for halide
what is the test for carbonates?
add a dilute acid, if it bubbles and fizzes = positive for carbonate
