experimental techniques Flashcards
apparatus suitable for measuring time
stopwatch
apparatus suitable for measuring temp
thermometer
apparatus suitable for measuring mass
digital mass balence
suitable apparatus for measuring volume
volumetric pipette
burette
measuring cylinder
gas syringe
advantages of stopwatch
measures up to 0.01 s
digital
advantages of volumetric pipette
measured a fixed volume of liquids ACCURATELY
measures up to 0.1cm3
more accurate than measuring cylinder
disadvantages of volumetric pipette
hard to use
only measures fixed volume
advantages of gas syringe
easy to set up
keeps gas dry
disadvantages of gas syringe
limited gas collected
delicate and expensive
advantages of thermometers
measures to the nearest degree
advantages of measuring cylinder
measures up to 0.01 cm3
more accurate than a beaker
disadvantages of a beaker
holds verities of volumes
assists chemical procedures that involve heating
heating
stirring
advantages of a beaker
calculates an estimate not an accurate liquid volume
advantages of burette
contains propper volume readings of VARIABLE VOLUMES
measures to nearest 0.1cm3
accurate
disadvantages of burette
hard to read
larger compared to a pipette
what is a solvent
solvent as a substance that dissolves a solute
what is a solute
solute as a substance that is dissolved in a
solvent
what is a solution
solution as a mixture of one or more solutes
dissolved in a solvent
what is a saturated solution
saturated solution as a solution containing
the maximum concentration of a solute
dissolved in the solvent at a specified
temperature
what is residue
residue as a substance that remains after
evaporation, distillation, filtration or any
similar process
what is a filtrate
filtrate as a liquid or solution that has passed
through a filter
What materials do you need for an acid–base titration
(a) burette
(b) volumetric pipette
(c) suitable indicator
Describe how to identify the end-point of a
titration using an indicator
end point is determined by change of colour
methyl orange: orangy in acid yellow in base
define a locating agent
it is used in colourless substances to spot he different compounds in the colourless solution
the one that is the highest on the paper is??
the most soluble
what does it mean if the spot doesnt move from the pencil start line?
insoluble
what does it mean if there are two spots in the same height?
theyre the same compound as the same compound have the same solubilty
why is the substance that travels the furthest is also the more soluble?
because it implies that it is the least attracted to the paper so it just moves upwards
state the Rf value formula
distance moved by spot/ distance moved by solvent
what does it mean if we get a number over 1 when calculating the rf value?
that it’s not right!! it’s always under 1
What is filtration
used to separate an insoluble solid from a liquid
what is simple destillation
what is crystallisation
what is fractional distillation
