Mixtures
What is the best option for separating iron powder and sawdust? (have the same particle sizes)
magnetism
(a magnet will attract the iron powder but not the sawdust)
What kinds of mixtures can chromatography separate?
Solutions and other homogeneous mixtures (inks, dyes, etc.)
What equipment do you need for filtration?
A funnel, filter paper and a beaker / flask
A puddle disappearing the day after a rain storm is an example of what?
Evaporation
What physical property does distillation use to separate substances?
Differences in boiling points
What helps separate sand & river water from gold nuggets?
Panning (a type of decantation)
What property does chromatography separate mixtures by?
Affinity and/or solubility (like dissolves like)
What can filtration separate?
Heterogeneous mixtures such as an insoluble solid from a liquid (e.g. sand from water, precipitate from water, particles from air)
What does evaporation separate?
A soluble solid solute from a liquid solvent
What are the state changes that occur in distillation (from start to finish)?
1. boiling (liquid to gas)
2. condensation (gas to liquid)
What can you add to a magnet to make it more magnetic?
Electricity
Jane separates ink using very polar solvent and slightly polar filter paper. If pigment "a" moves farther up than pigment "b", which is more polar?
Pigment "a". It's more like the very polar solvent and less like the slightly polar paper (like dissolves like)
Describe the steps of filtration
(1) Fold filter paper in fourths (2) Place filter paper in a funnel and the funnel over a flask (3) Pour the mixture into the filter paper (4) Allow the liquid to flow through the paper and the solid to collect on top
True or False? CuSO4(s) crystals can be separated from water in CuSO4(aq) using evaporation
True
What is the name of the equipment that cools down the boiled vapor?
condenser
True or false? All metals are magnetic.
False! Only Fe, Ni and Co (and their alloys) are magnetic
What is the 'mobile phase' and the 'stationary phase' in paper chromatography?
Mobile phase = solvent/eluent
Stationary phase = paper
How is decantation different than filtration?
Decantation separates by density
Filtration separates particles by size
What can you do to speed up the process of evaporation?
Increase the temperature
What is the main difference between evaporation and distillation?
distillation recovers the evaporated substance (nothing is lost)
What property does centrifugation separate mixtures by?
Centrifugation separates by density (or buoyancy)
Describe the steps to perform paper chromatography
(1) Put sample dots on the paper (2) Hang the paper in a container (3) Only let the bottom of the paper touch the solvent (4) Remove the paper after the solvent traveled ⅔ to ¾ up
Why are you unable to use a filter to separate a liquid homogeneous mixture?
The particle sizes are all the same in a homogeneous mixture (atomic scale), so it would all go through the filter without separating the different parts
When we evaporate an aqueous solution to separate the components, what states are present when it is finished?
water vapor is a gas and the solute will be solid or liquid
A mixture contains two liquids with boiling points of 100°C and 50°C. What temperature do you use to start the distillation process?
You start by heating the mixture to 50°C so only that liquid boils