UNIT 37

• DESCRIBE / EXPLAIN HOW PERSONAL AND SALON HYGIENE MEASURES HELP TO PREVENT CROSS INFECTION

• ANALYSE THE IMPORTANCE OF COOLING EFFECT OF EVAPORATION WITH REFERENCE TO BODY AND BEAUTY THERAPY

• EXPLAIN THE MEANING OF ‘MIXTURE’, ‘SOLUTION’, ‘SOLVENT’, ‘SOLUTE’, ‘EMULSION’ AND ‘FOAM’, USING EXAMPLES FROM BEAUTY THERAPY

• EXPLAIN THE MEANING OF ‘ACID’, ‘ALKALI’, ‘PH’, ‘OXIDISING AGENT’, USING EXAMPLES FROM BEAUTY THERAPY

• STATE POTENTIAL HAZARDOUS AND VOLATILE SUBSTANCES USED IN THE SALON OR LABORATORY

• DESCRIBE HOW POTENTIAL HAZARDOUS AND VOLATILE SUBSTANCES SHOULD BE USED AND STORED IN THE SALON OR LABORATORY

DESCRIBE / EXPLAIN HOW PERSONAL AND SALON HYGIENE

MEASURES HELP TO PREVENT CROSS INFECTION

• EXPECTED STANDARD OF PERSONAL HYGIENE:• HOW DOES THIS PREVENT CROSS-INFECTION?•  EXPECTED STANDARD OF SALON HYGIENE• HOW DOES THIS PREVENT CROSS-INFECTION?

ANALYSE THE IMPORTANCE OF COOLING EFFECT OF

EVAPORATION WITH REFERENCE TO BODY AND BEAUTY THERAPY

EXPLAIN THE MEANING OF ‘MIXTURE’, ‘SOLUTION’, ‘SOLVENT’, ‘SOLUTE’, ‘EMULSION’ AND ‘FOAM’, USING EXAMPLES FROM BEAUTY THERAPY• THE FOLLOWING ARE ALL TYPES OF MIXTURES1.SOLUTION 2. COLLOIDAL 3.SUSPENSION • THEY ARE CONSIDERED MIXTURES AS THEY ARE A

COMBINATION OF TWO OR MORE PARTICLES.

SOLUTIONS, SUSPENSIONS, & COLLOIDS

MIXTURE CHEMISTRYSOLUTIONS A SOLUTION IS A EQUAL MIXTURE OF TWO OR MORE COMPONENTS. THE DISSOLVING AGENT IS THE SOLVENT. THE SUBSTANCE WHICH IS DISSOLVED IS THE SOLUTE.

EXAMPLE: SUGAR AND WATER

THEY ALL SOUND THE SAME!

• SOLUTION - THE MIXTURE FORMED WHEN A SUBSTANCE DISSOLVES IN IT

• SOLUTE - THE SUBSTANCE THAT DISSOLVES• SOLVENT - THE LIQUID IN THE SOLUTION

• DISSOLVE - MIXING OF A SUBSTANCE IN A LIQUID• SOLUBLE - A SUBSTANCE WHICH CAN DISSOLVE (MIX IN A LIQUID)• INSOLUBLE - A SUBSTANCE WHICH CANNOT DISSOLVE (MIX IN A

LIQUID)

Solute Solvent Solution

SUSPENSIONS

THE PARTICLES IN SUSPENSIONS ARE LARGER THAN THOSE FOUND IN SOLUTIONS. COMPONENTS OF A SUSPENSION CAN BE EVENLY DISTRIBUTED BY A MECHANICAL MEANS, LIKE BY SHAKING THE CONTENTS, BUT THE COMPONENTS WILL SETTLE OUT.

EXAMPLE: OIL AND WATER

COLLOIDS• PARTICLES INTERMEDIATE IN SIZE BETWEEN THOSE FOUND IN

SOLUTIONS AND SUSPENSIONS CAN BE MIXED SUCH THAT THEY REMAIN EVENLY DISTRIBUTED WITHOUT SETTLING OUT.

LIQUIDS, SOLIDS, AND GASES ALL MAY BE MIXED TO FORM COLLOIDAL DISPERSIONS.

• AEROSOLS: SOLID OR LIQUID PARTICLES IN A GAS.EXAMPLES: SMOKE IS A SOLID IN A GAS. FOG IS A LIQUID IN A GAS. .

• EMULSIONS: LIQUID PARTICLES IN LIQUID.EXAMPLE: MAYONNAISE IS OIL IN WATER.

• GELS: LIQUIDS IN SOLID.EXAMPLES: GELATIN IS PROTEIN IN WATER. QUICKSAND IS SAND IN WATER.

Telling Them Apart

• COMPONENTS OF SUSPENSIONS WILL EVENTUALLY SEPARATE.

• COLLOIDS CAN BE DISTINGUISHED FROM SOLUTIONS USING THE LIGHT

• A BEAM OF LIGHT PASSING THROUGH A TRUE SOLUTION, SUCH AS AIR, IS NOT VISIBLE.

• LIGHT PASSING THROUGH A COLLOIDAL DISPERSION, SUCH AS SMOKY OR FOGGY AIR, WILL BE REFLECTED BY THE LARGER PARTICLES AND THE LIGHT BEAM WILL BE VISIBLE.

SOLUTION, COLLOID OR SUSPENSION??

Beaker A Beaker B Beaker C

There is a solution in beaker A (as it is transparent), even though it is coloured red

Milk (beaker B) contains a colloid water + fat. The fat has not completely dissolved in the liquid as it is cloudy

Flour is insoluble. This is why it settles at the bottom (stirring makes it go cloudy, but eventually the flour particles settle to the bottom)

A solution is always transparent – even if it has a colour If our liquid remains cloudy, then the solute has not

completely dissolved If a substance will not dissolve (insoluble) then it will settle

and be obvious

HOW DO WE KNOW?

FILL IN THE WORDS!

• READ THE FOLLOWING PASSAGE AND FILL IN THE KEY WORDS.

If particles are combined, we have a ________. If you mix _____with water then the grains seem to disappear. This is because the grains have split up and mixed with the water. They have ___________. A substance that ______ is said to be ________.

A solid dissolved in liquid makes a _______. In a ________the liquid is called the ________, and the solid is called the _____.

A solid that does not dissolve in a liquid is called ________. If a solid has completely dissolved in a liquid, then the ________is always __________, even if it has a colour.

If particles are combined, we have a mixture. If you mix salt with water then the grains seem to disappear. This is because the grains have split up and mixed with the water. They have dissolved. A substance that dissolves is said to be soluble.

A solid dissolved in liquid makes a solution. In a solution the liquid is called the solvent, and the solid is called the solute. A solid that does not dissolve in a liquid is called insoluble. If a solid has completely dissolved in a liquid, then the solution is always transparent, even if it has a colour.

Solution - the mixture formed when a substance dissolves in itSolute - the substance that dissolvesSolvent - the liquid in the solution

Dissolve - mixing of a substance in a liquidSoluble - a substance which can dissolve (mix in a liquid)Insoluble - a substance which cannot dissolve (mix in a liquid)

WHAT IS FOAM? SOLUTION, COLLOID OR SUSPENSION?

EXPLAIN....

Foam is a dispersion of a gas in a liquid (liquid foams) or in a solid (solid foams).

Among the liquid foams, we have the ones produced by soaps and detergents, and various foods such as wine, beer and many others.

Among the solid foams we have Pumice stone, earthenware, sponges, expanded plastics like expanded polystyrene and expanded polyurethane.

.

PH AND ACIDITY• PH AND ACIDITY• AN ACID IS A SUBSTANCE WHICH DISSOCIATES TO PRODUCE

HYDROGEN IONS IN SOLUTION. A BASE (ALKALINE) IS A SUBSTANCE WHICH PRODUCES HYDROXYL IONS IN SOLUTION. IT CAN EQUALLY BE STATED THAT AN ACID IS A SUBSTANCE WHICH DONATES A PROTON AND A BASE IS A SUBSTANCE WHICH ACCEPTS A PROTON.

• THE SYMBOL PH IS USED TO DENOTE ACIDITY; IT IS INVERSELY RELATED TO HYDROGEN ION CONCENTRATION.

• NEUTRALITY IS PH 7ACIDITY IS LESS THAN PH 7ALKALINITY IS MORE THAN PH 7

• WHAT IS AN ACID?• WHAT MUST I MEASURE ON THE PH SCALE?• WHAT COLOUR DO I GO ON LITMUS PAPER?•  AM I DANGEROUS?• WHERE AM I FOUND?AM I USED IN BEAUTY THERAPY? WHERE?

• WHAT IS AN ALKALI?•  WHAT MUST I MEASURE ON THE PH SCALE? • WHAT COLOUR DO I GO ON LITMUS PAPER? • WHERE AM I FOUND?•   I USED IN BEAUTY THERAPY? WHERE?• WHAT IS AN “OXIDIZING AGENT”?• WHAT DO I DO?• HOW DO I DO THIS?

• STATE POTENTIAL HAZARDOUS AND VOLATILE SUBSTANCES USED IN THE SALON OR LABORATORY

• DESCRIBE HOW POTENTIAL HAZARDOUS AND VOLATILE SUBSTANCES SHOULD BE USED AND STORED IN THE SALON OR LABORATORY

• USED:• STORED: