Experimental chemistry Flashcards
(15 cards)
what is the SI unit for time
seconds (s)
what is the SI units of temp.
kelvin (k)
what is the SI units for length
metre (m)
what is the SI units of mass
kilogram (kg)
whats the SI units of volume
cubic metre (m^3)
list the three types of methods for collecting gases
water displacement
downwards delivery
upwards delivery
what physical properties affects the methods for gas collection
solubility (how easily gas dissolves in water) and density (how dense the gas is compared to the surrounding)
when to use the method of water displacement?
when the gas in water is insoluble to slightly soluble
density do not affect the method of collection
example of gases (hydrogen, oxygen, carbon dioxide)
when to use the method of downwards delivery
when the gas in water can be soluble or insoluble
when the gas is denser than air
example chlorine, hydrogen chloride, sulfur dioxide
when to use the method of upwards delivery
when the gas in water can be soluble or insoluble
when the gas is less dense than air
example ammonia
separation techniques or solid-solid mixture (4 points)
magnetic attraction
sieving
using suitable solvents
sublimation
separation techniques or solid-liquid mixture (4 points)
filtration
evaporation to dryness
crystallisation
simple distillation
separation techniques or liquid-liquid mixture (3 points)
separating funnel
chromatography
fractional distillation
when to use magnetic attraction (solid-solid)
when one of the solid components have metal properties
when to use sieving method (solid-solid)
when the mixture consist of bigger and smaller particles1
