Chemistry - States of Matter and Mixtures Flashcards
Describe the arrangement and motion of particles in a solid
Vibrate around a fixed position
Describe the arrangement and motion of particles in a liquid
Move around each other randomly close together
Describe the arrangement and motion of particles in a gas
Move randomly far apart
What word describes the change of a solid into a liquid
melting
What word describes the change of a liquid to a gas
evaporation
What word describes the change of a gas into a liquid
condensation
What word describes the change of a liquid into a solid
freezing
What word describes the change of a solid into a gas
sublimation
Describe what happens to the stored energy of the particles when a solid changes to a liquid
stored energy increases (liquid has more energy than solid)
Describe what happens to the stored energy of the particles when a gas changes into a liquid
stored energy decreases (liquid has less energy than gas)
Chlorine has a boiling point of -34oC. Predict its state at room temperature
Gas (Room temperature (25oC, is higher than the boiling point)
Describe the difference between a pure and impure substance
pure substance is made of only one type of atom, has a uniform structure. Impure substance contains different types of atoms.
Describe the difference in the melting point of a pure and impure substance
A pure substance has a single sharp melting point. An impure substance melts over a range.
Explain how distillation separates a mixture of ethanol and water
Ethanol has a lower boiling point than water Ethanol evaporates first Then condenses in the condenser
State the four methods of separation
Distillation Filtration Crystallisation Chromatography
Which separation technique could be used to separate a mixture of sand and water
Filtration as sand particles can’t fit through the filter paper
Which separation technique could be used to separate a mixture of coloured inks
Chromatography
Which separation technique could be used to separate a mixture of water and ink
Distillation
What is the mobile phase in chromatography
The solvent (water)
What is the stationary phase in paper chromatography
paper
Describe how to set up chromatography to separate the inks in a coloured pen
-Draw a line on a piece of chromatography in pencil -Put a dot of the pen on the pencil line -Suspend the paper in the chromatography tank so the paper just touches the water -Wait for the inks to separate -Calculate the Rf values
What is the equation to calculate Rf value
Rf value = distance substance moved ÷ distance solvent moved
What are the three stages of water treatment
Sedimentation, filtration, chlorination
Describe sedimentation of water
Sand and grit are allowed to settle at the bottom of the tank
Describe filtration of water
Insoluble solids are removed from the water
Describe chlorination of water
Chlorine is added to the water to kill bacteria
Explain how sea water is made potable using distillation
sea water is heated until it evaporates water condenses leaving salt behind
Explain why distilled water must be used for analysis
Tap water contains dissolved salts which can give false results
What conclusions can be made from this chromatogram
- S contains six / 6 colourings
- P contains five / 5 colourings
if neither of first 2 bullet points given allow 1 mark for S contains more colours than P or converse
• both S and P contain the same
five / 5 colourings
- both contain W and Y
- both sweets (may) cause hyperactivity
ignore unsafe
• neither contain X and Z
Calculate the Rf value of W
3 ÷ 10 = 0.3
Label parts A and B on the diagram
A - round bottomed flask
B - condenser
Does this melting point graph show a pure or impure substance
Pure as it has a sharp melting point (horizontal line)
