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Brown's Chemistry Clinic
KS3
SCIENCE-Chemistry QCA
Unit 7H Solutions
KS3 Quizzes or task sheets based on this summary: four word-fill worksheets * multiple
choice quiz * X-word * matching
pair quiz (printout/drag-drop version)
ALL KS3 SCIENCE
QUIZZES * KS3 Chemistry Quizzes and
full
list of GCSE Revision Notes on Chemistry, Earth Science and Radioactivity
* EMAIL
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More advanced GCSE work based on 7H:
GCSE m/c tests *
Aqueous
Chemistry * Elements, Compounds
and Mixture Separations
7H
Solutions (solubility, salt purification and
chromatography etc.)
 QCA 7H "Solutions"
Multiple Choice Questions for Science SATs revision
on particle models of mixtures, rock salt
purification, solute/solvent/solution/solubility, methods of separating
mixtures - filtration, evaporation, distillation, chromatography.
7Hwf1-4
four handy linked word-fill
worksheets * 7Hwf2 * 7Hwf3 *
7Hwf4 *
The BIG hard
on-line crossword puzzle 
(with letter hints), printout of the BIG version
OR the smaller
EASIER
(with letter hints),
printout
of the smaller EASIER version
matching pair exercise on keywords or
drag
& drop version or printout
The
7H
crossword and word-fill
In this unit you should learn to ...
- extend your knowledge of dissolving and the separation of the components
of a solution and relate this to particle theory
- begin to distinguish between a ‘pure’ substance and a mixture
- apply the particle model of solids, liquids and gases in a range of
contexts
- make measurements of temperature and mass
- describe and interpret patterns in graphs and chromatograms
- make predictions from graphs and data about solubility
- investigate, and explain, how a sample of pure salt can be obtained from a sample of
rock salt, evaluating the method in terms of salt obtained
- classify some solids as soluble or insoluble and
explain the meaning of the term ‘saturated solution’
- describe how mixtures
can be separated by distillation and chromatography
- use the
particle model to explain what happens when a solid dissolves in water,
explaining why mass is conserved
Its handy if you ...
- have had experience of dissolving solids in water and know that not all
are soluble
- have separated mixtures of solids and liquids
- know that not all liquids contain water
- know that all materials are made up of very small particles
Some important words for you to understand, use
and spell correctly ...
- words and phrases relating to dissolving, eg solution, solute,
solvent, soluble, insoluble, saturated solution
- words and phrases relating to the separation of mixtures,
eg
filtration, distillation, chromatography, chromatogram
- words and phrases relating to explanations using the particle model,
eg
particle, attracted, mixing, mingling
- words and phrases relating to scientific enquiry,
eg prediction,
evaluate, interpret
- words with similar spelling but different meanings, and use them in a
consistently correct way, eg affect, effect
How can we tell whether a liquid is a mixture?
- that some solids dissolve in liquids and others do not
- that many common materials are mixtures
and mixtures can be separated
- selection of liquids, eg distilled water
or deionised water, seawater, a suspension of chalk in water, ethanol,
copper sulphate solution, and ask is it
water? is it pure?
- devise techniques, eg filter, evaporate to dryness, to find out
whether a liquid is a mixture or not
- learn the terms ‘soluble’, 'solvent',
'solution‘, 'insoluble’ and ‘solute’
- name some solids that dissolve in water and some that do not
- identify the components of some mixtures,
eg seawater is water
with salt and other solids dissolved in it
How much salt can we get from rock salt?
- use knowledge about separating mixtures to obtain a sample of
salt from rock salt
- that salt comes from a variety of sources and has many uses
- although
the salt dissolves, it doesn’t disappear!
- the occurrence, extraction
and uses of salt - relate this to processes used in the laboratory
- explain why the mass of the salt sample was less than the mass of
rock salt
What happens to the solute when a solution is made?
- that when a solute dissolves, mass is conserved
- that when a solute dissolves, the solute and solvent particles
intermingle
- draw the water particles (solvent) before and after the
addition of salt (solute) and use this to explain, eg that mass is
conserved, or why filtering will not separate the salt
- mixing two liquids,
eg
ethanol and water or oil and water - which mix/dissolve in each other?
How can we separate solvents from solutes?
- distillation can be used to separate a liquid from the
solids which are dissolved in it eg ink solution
- distillation is a process in which evaporation/boiling of a liquid
is followed by condensation by cooling
- it is often very important to separate and collect
the liquid, eg in purifying water.
- how they could you obtain drinkable water from
seawater?, eg in an area
where there is a lot of seawater, but no fresh water.
- describe how the solvent could be separated from the solute by
distillation
- distillation separation works because the solvent changes to a
gas and back to a liquid, but the solute does not evaporate
- find out about desalination
plants or how distillation is used to separate liquids, eg crude oil.
How can chromatography separate and identify substances in mixtures?
- that a mixture of two or more solutes which are soluble in a
particular solvent can be separated and identified by chromatography
- how to separate the different coloured compounds in
an ink mixture on blotting or filter paper, using a wick of the paper
dipped into the solvent (water).
- why do different coloured ink solids travel different
distances?
- use particle ideas to explain how chromatography works
- find out at home whether food or sweet
colourings, inks in felt-tip pens or markers are single dyes or mixtures
of dye.
- how chromatography can be used to compare mixtures of solutes
- how scientists use evidence from chromatography
- forensic science, medical analysis
- chromatography can be used with non-coloured
solutes - but you need to make the different solutes 'show up' in some way
eg add a chemical that makes them coloured or shine on ultra-violet light to
make them 'glow'
Is there a limit to the amount of solid that will dissolve in a liquid?
- when a solid is added to a liquid, eventually no more will
dissolve (a saturated solution) - there is limit to how much can dissolve in a particular
volume of solvent - how can you tell no more dissolves?
- that different masses of different solids dissolve in the same
volume of a particular solvent
- that solids can dissolve in liquids other than water
- state that some solids dissolve more in some liquids than others
- different solvents, different solubility
What else affects solubility?
- that many solutes are more soluble at higher temperatures
- you can use tables of data to calculate quantities of material to use
(see examples)
- to make comparisons, identify patterns and make predictions from
graphs (see examples)
- cooling a saturated solution, eg of benzoic acid, which forms crystals as it cools.
- state that a saturated solution has been formed when crystals
appear
- state the solubility at a particular temperature,
eg at 70°C,
3g of the solid dissolved in 100g of water
- it is important to draw the
distinction between dissolving in terms of ‘how much’ and ‘how fast’.
* KS3 chemistry Key Stage 3 SATs revision * KS3 chemistry Key Stage 3
SATs revision * KS3 chemistry Key Stage 3 SATs revision * KS3 chemistry
Key Stage 3 SATs revision *
ks3 science ks3
science ks3 science ks3 science ks3 science ks3 science ks3 science ks3
science ks3 science ks3 science ks3 science ks3 science ks3 science SITE PURPOSE: EDUCATION
- online learning or 'self-private-tuition' using revision notes,
quizzes, practice SAT/SATs test/tests. KS3 SCIENCE Y7 (Year 7), Y8 (Year
8), Y9 (Year 9) Biology-Chemistry-Physics exams. REVISING at Doc Brown's
Chemistry Clinic via HOMEPAGE in secondary school/schools, college/colleges,
academy/academies or home self-study and may help
with 1st year undergraduate university chemistry courses. Hopefully it will encourage
interest and understanding of Chemistry and Earth Science
in any country of the world, though the site is written entirely in English. The website is designed to help
students/teachers revise, learn or teach the chemistry for English National QCA criteria assessment levels for KS3 SATs Science-biology/chemistry/physics (SAT revision levels 3-5
or 5-7 examinations) for secondary schools and colleges. The site does not support the content of
England, Wales or Northern Ireland primary science for KS1 and KS2, nor
does it support KS3 English and Mathematics (Maths). The notes should
provide some background theory for a coursework assignment or project.
BUT please note that my on-line revision notes and quizzes are no
substitute for good classroom teaching-lecturing and thorough studying
of your own notes and textbooks, practicing past papers and a copy of
the syllabus which are readily downloaded from the examination board
sites, but I hope here and there they will lend a tutoring hand on some
topic, unit, module etc. For final revision you have to be
intellectually honest about what you don't know or follow, YOU have to
take the stuff to pieces, analyse what you do/do not understand and
reconstruct it so it all makes sense in the end. There is no other way,
there are no magic secrets on how to revise and learn, its mainly down
to hard work and just good old fashioned study and employing
teach-yourself strategies without the need for extra tutors and tutoring
lessons. I also think there is too much hit and miss revision using past
papers (which I do NOT supply) and not enough systematic revision. I also hope it will help teachers in planning lessons and
developing schemes of work for science-chemistry. There are no lesson
plans on the site but there are plenty of quizzes to incorporate into
classroom activities whether photocopied or on electronic whiteboard
projector for use as self-tuition-assessment purposes and a variety of
teaching and learning styles and the images may be used in Microsoft
Word documents and PowerPoint projections. The site seems to be used by
a large number of home study tutors, particularly the revision notes. An
individual tutor may print out the notes for science-chemistry
learning teaching-tuition purposes and for background material for
assignments and projects. I have no interest or time in
producing WORD.doc or xxxx.pdf files of the notes at the moment. Neither have I time to write up many practical
laboratory experiments ('lab'-'labs') at the moment, but the notes contain lots
of background information of chemical reactions in terms of
observations-balanced equations-reactants-products-theory etc. I also find it
difficult to recommend specific exam websites or syllabus textbooks, it depends exactly on
what you need, what you have time for, and there are so many of them to choose
from and I do not supply past examination papers for classes. The sites
resources include revision notes, quizzes and worksheets which provide
support for home study or tuition for homework and coursework help e.g.
science investigations for any of the key stage three 3 courses
indicated, but I do not supply lesson plans. science Dr W P Brown ks3
10-11-2007 ks3 science ks3
science ks3 science ks3 science ks3 science ks3 science ks3 science ks3
science ks3 science ks3 science ks3 science ks3 science ks3 science
* KS3 chemistry Key Stage
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