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Natural sciences

Form, reaction and alteration of materials

Educator section

Memorandum

1. In which glass is the sugar dissolved quickest?

  • In the glass with warm water.

2. Explain why this happens.

  • The solubility of a substance is affected by the temperature.

Assignment 13:

  • (Groupwork)
  1. How many teaspoons of sugar could you dissolve into the glass of water?
  • The amount depends on the individual experiment.
  • Discus in your group what you could do to dissolve more sugar into the water.
  • The water (solution) can be heated.
  • The sugar crystals (dissolved substance) and be made finer.

Assignment 14:

Observation: The water has evaporated and small crystals have been formed: copper sulphate crystals. Under the microscope the crystals appear as small blocks or cubes.

Conclusion: When a solution is left to stand the opposite of dissolving occurs. The dissolved substance crystallises into a solid in the form of crystals.

Assignment 15:

  1. Is the amount and type of solvent the same in all three cases?
  • Yes
  • Which substance was dissolved the least after the first teaspoon?
  • Corn meal
  • Is corn meal insoluble?
  • Yes

4. Which substance dissolved best?

  • Salt

Conclusion: Not all substances are equally soluble.

Assignment 16:

  1. What do you see?
  • Oil does not dissolve. You continue to see drops of oil on the water

2. Where is the oil?

  • While you are stirring it seems that the oil is mixed with the water, but the moment that you stop stirring the oil floats to the surface of the water.

3. Can oil dissolve in water?

  • No

4. What is the reason for the answer above?

  • Particles of oil are strongly attracted to each other. Water particles cannot move in between the oil particles, so oil is not soluble in water.

Assignment 17:

1. What happens?

  • The naphthalene flakes do not dissolve in water but do dissolve in mentholated spirits.

2. Can you explain why this happens?

  • Naphthalene flakes are not soluble in water.

3. Complete.

  • Naphthalene is easily dissolved in mentholated spirits but is not soluble in water

Leaner section

Content

Activity: to determine the factors that affect the solubility of materials [lo 1.1, lo 1.2, lo 1.3]

The solubility of a material is determined by:

  • temperature;
  • type of material; and
  • type of solvent.

ASSIGNMENT 12

To determine how temperature affects solubility.

Requirements: Sugar

A glass of cold water

A glass of warm water

A teaspoon

  • Put one teaspoonful of sugar into the glass of cold water and another into the glass of warm water.
  • Do not stir the water.
  • Observe what happens.

What do you observe?

1. In which glass is the sugar dissolved the quickest?

_____________________________________________________________________

2. Explain why this happens.

_____________________________________________________________________

REMEMBER THE FOLLOWING IN CONNECTION WITH SOLUBILITY

Sugar is SOLUBLE in water.

The sugar is the DISSOLVED substance.

The water is the SOLVENT.

The sugar water is the SOLUTION.

HEAT increases the process of solution.

  • A saturated solution:

Water can only take a certain amount of a dissolved substance like sugar. When the water can not take more of the substance, we say that it is a saturated solution.

Questions & Answers

current economic plans (MDGS) needs
Ajijola Reply
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surajkumar
What is economic
Joeali Reply
What is the importance of study economics
Wilma
Economic is the study of how humans make decisions in face of sacristy
Wilma
economics is the study of how humans makes decision in the face of scarcity
Kpienta
economics is the study of human behaviour when faced with difficult situation example when goods and services are scarcity.
Sydney
what is Economic
Dauda Reply
what is 4ps of economic?
thomas Reply
production place Price product
Benedict
Criticism of elasticity
Siddikur Reply
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Gyamfi Reply
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Gyamfi
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Bethel
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jackie
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Abubakar
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unemployment refers to the ability for someone who is capable and willing to work but could not find a job..
Mnoko
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Dennis
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thomas
What is stock market?
JOHN Reply
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Ruth Reply
Short-run average fixed cost (SRAFC) Short-run average total cost (SRAC or SRATC) Short-run average variable cost (AVC or SRAVC) Short-run fixed cost (FC or SRFC) Short-run marginal cost (SRMC) Short-run total cost (SRTC)
Romy
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Popoola Reply
what do you understand by Ceteris Paribus?
Gabriel Reply
the external factor will remained constant, except the price
Hasib
everything being equal
Chenwi
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Nikita Reply
uses of microeconomics
Nikita
Adam Smith's definition of economics
Sylvia Reply
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Amjad
this is a situation whereby a nation's outcome or available resources are not enough to the people thereby causing scarcity
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NABUBOLO Reply
it's quantity demand and quantity supplied that's called equilibrium
Romy
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NABUBOLO
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NABUBOLO
define the elasticity
NABUBOLO
explain different types of elasticity
NABUBOLO
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Romy
elasticity is the measurement of the percentage change of one economic variable in response to a change in another
Romy
Cross Elasticity of Demand (XED) Income Elasticity of Demand (YED) Price Elasticity of Supply (PES)
Romy
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Romy
I need to know everything about theory of consumer behavior
Grace
Romy, what is microeconomic?
thomas
What is Economic please
Dauda
Thomas, microeconomics is the study of how consumers, workers, and firms interact to generate outcomes in specific markets
Kieran
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Kieran
How does one analyze a market where both demand and supply shift?
Gabriel Reply
That's equilibrium market
Ramon
but an equlibrum can appear twice on the same market... both in Movement along the Demand/supply curve of shift in the Curve
Gabriel
I Mean on the same curve..
Gabriel
how can consumer surplus be calculated
Franklyn
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Source:  OpenStax, Natural sciences grade 6. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11079/1.1
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