DRIPPING WATER TAP

LESSON 12: TYPES OF MIXTURES

HOW ARE MIXTURES CLASSIFIED?

A MIXTURE CONSISTS OF TWO OR MORE PURE SUBSTANCES. VARIOUS TERMS ARE USED WHEN DESCRIBING MIXTURES

HOMOGENEOUS: USED TO DESCRIBE SUBSTANCES THAT LOOK THE SAME THROUGHOUT. HOMOGENEOUS SUBSTANCES HAVE ONE PHASE AND UNIFORM COMPOSITION.

HETEROGENEOUS: USED TO DESCRIBE SUBSTANCES IN WHICH YOU CAN SEE MORE THAN ONE COLOR OR TYPE OF MATTER. HETEROGENEOUS SUBSTANCES HAVE MORE THAN ONE PHASE AND A NONUNIFORM COMPOSITION.

PHASE: IS A VISIBLY DISTINCT PORTION OF MATTER

TYNDALL EFFECT: IS SEEN WHEN A MIXTURE MAKES A BEAM OF LIGHT VISIBLE.

THERE ARE SEVERAL TYPES OF MIXTURES. THEY ARE:

  • SOLUTIONS
  • SUSPENSIONS
  • EMULSIONS
  • COLLOIDAL DISPERSIONS

SOLUTIONS: ARE MIXTURES MADE BY MIXING A SOLUTE AND A SOLVENT. THE SOLUTE IS THE SUBSTANCE THAT DISSOLVES. THE SOLVENT IS THE SUBSTANCE THAT DOES THE DISSOLVING. SOLUTIONS ARE HOMOGENEOUS AND DO NOT SHOW THE TYNDALL EFFECT. (HELP WITH SOLUTE AND SOLVENT)

SUSPENSIONS: ARE HETEROGENEOUS MIXTURES OF A SOLID AND A LIQUID IN WHICH THE SOLID DOES NOT DISSOLVE. SUSPENSIONS WILL SETTLE WHEN LEFT STANDING UNDISTURBED. SUSPENSIONS WILL SHOW THE TYNDALL EFFECT.

EMULSIONS: ARE A SPECIAL TYPE OF SUSPENSION. THIS MIXTURE CONSISTS OF TWO LIQUIDS THAT DO NOT MIX. SINCE THE LIQUIDS DO NOT MIX, EMULSIONS ARE HETEROGENEOUS. EMULSIONS WILL SETTLE INTO LAYERS WHEN THEY ARE LEFT STANDING UNDISTURBED. EMULSIONS WILL SHOW THE TYNDALL EFFECT.

COLLOIDAL DISPERSIONS: ARE MIXTURES WITH CHARACTERISTICS PART WAY BETWEEN A SOLUTION AND A SUSPENSION. COLLOIDAL DISPERSIONS MAY APPEAR HOMOGENEOUS BUT ARE ACTUALLY HETEROGENEOUS. COLLOIDAL DISPERSIONS DO NOT SETTLE WHEN LEFT STANDING UNDISTURBED FOR A PERIOD OF TIME. COLLOIDAL DISPERSIONS DO SHOW THE TYNDALL EFFECT.

EXAMPLES:      
SOLUTIONS SUSPENSIONS EMULSIONS COLLOIDAL DISPERSIONS
SALT AND WATER SOIL AND WATER OIL AND VINEGAR LIQUID LAUNDRY STARCH AND WATER
ALCOHOL AND WATER SAND AND WATER KEROSENE AND WATER

FINE POTTERY CLAY AND WATER

COPPER SULFATE AND WATER CLAY AND WATER OIL AND WATER MAYONNAISE

VISIT ONE, NONE OR ALL OF THESE SITES TO GAIN A BETTER UNDERSTANDING OF THE DIFFERENT TYPES OF MIXTURES AND THE TYNDALL EFFECT.

SITE A: SCROLL DOWN TO FIND THE DIFFERENT TYPES OF MIXTURES AT THIS EARTHLINK SITE

SITE B: READ ABOUT THE TYNDALL EFFECT

SITE C: SILVERGEN SITE SHOWING THE TYNDALL EFFECT WITH LASERS

ACTIVITY

PART 1:

CHECK OUT THE POSEIDON SOFTWARE AND INVENTION SITE. AS YOU READ, LOOK FOR THE LINK TO OOBLECK.

IF YOU DIDN'T LOOK AT THE RECIPE FOR OOBLECK, THEN GO BACK TO THE SITE ABOVE AND NOTE THE RECIPE FOR OOBLECK. MAKE THE OOBLECK AND NOTE ITS PROPERTIES. REMEMBER THAT OOBLECK IS AN EXAMPLE OF A COLLOID.

PART 2:

MIX UP AN EXAMPLE OF A SOLUTION, SUSPENSION, EMULSION AND COLLOIDAL DISPERSION.

TEST WHETHER EACH OF THESE MIXTURES SHOWS THE TYNDALL EFFECT BY SHINING A FLASHLIGHT AT THE SIDE OF THE CONTAINER. IF THE MIXTURE MAKES THE BEAM OF LIGHT VISIBLE THEN THE MIXTURE SHOWS THE TYNDALL EFFECT.

PART 3:

NOW, TRY SOME QUESTIONS TO DETERMINE WHETHER YOU RECOGNIZE THE VARIOUS TYPES OF MIXTURES.

CLICK THE WHITE DOT BELOW THAT INDICATES THE CORRECT ANSWER. IF YOU GET MOST OF THE ANSWERS CORRECT THEN IT SHOWS THAT YOU HAVE A GOOD UNDERSTANDING OF THE TERMS DISCUSSED ABOVE.

1. SALT AND WATER IS AN EXAMPLE OF A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
2. A MIXTURE OF CLAY AND WATER IS AN EXAMPLE OF A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
3. A MIXTURE OF ALCOHOL AND WATER IS AN EXAMPLE OF A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
4. A MIXTURE MADE OF OIL AND WATER IS AN EXAMPLE OF A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
5. A MIXTURE IS DESCRIBED AS A HETEROGENEOUS LIQUID WHERE TWO LIQUIDS ARE VISIBLE AND THE MIXTURE SHOWS THE TYNDALL EFFECT. THIS MIXTURE WOULD BE A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
6. A MIXTURE IS DESCRIBED AS LOOKING HOMOGENEOUS, NOT SETTLING WHEN LEFT STANDING UNDISTURBED AND DOES SHOW THE TYNDALL EFFECT. THIS MIXTURE WOULD BE CLASSIFIED AS A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
7. A MIXTURE IS DESCRIBED AS BEING HOMOGENEOUS BUT DOES NOT SHOW THE TYNDALL EFFECT. THIS MIXTURE WOULD CORRECTLY BE CLASSIFIED AS A:

SOLUTION
SUSPENSION
EMULSION
COLLOIDAL DISPERSION
8. WHICH OF THESE IS AN EXAMPLE OF A COLLOIDAL DISPERSION?

OIL AND VINEGAR
SOIL AND WATER
SALT AND WATER
LIQUID LAUNDRY STARCH AND WATER
9. IF YOU WANTED TO MAKE AN EMULSION, WHICH OF THE FOLLOWING SUBSTANCES WOULD YOU ADD TO WATER?

WATER
OIL
VINEGAR
ALCOHOL
10. IF YOU WANT TO MAKE A SOLUTION, WHICH WOULD YOU MIX WITH WATER?

WATER
OIL
SAND
ALCOHOL

ASSIGNMENT

CLASSIFY EACH OF THE FOLLOWING MIXTURES AS A SOLUTION, SUSPENSION, EMULSION OR COLLOIDAL DISPERSION. CLICK OUTSIDE THE WHITE BOX WHEN YOU ARE FINISHED TYPING YOUR ANSWER TO EACH QUESTION. THIS WILL LET THE COMPUTER KNOW THAT IT SHOULD CHECK WHETHER YOUR ANSWER WAS CORRECT OR NOT.

1. A GLASS OF WHOLE MILK
2. A GLASS OF POP

3. A CUP OF BLACK COFFEE

4. ITALIAN SALAD DRESSING

5. GRAVEL AND WATER

6. HOT CHICKEN LIPTON NOODLE SOUP

7. A GLASS OF COOL ICED TEA

8. KETCHUP

9. A GLASS OF ORANGE JUICE

10. A MIXTURE OF WATER AND DIESEL FUEL

ASSESSMENT

YOU WILL ASSESS YOURSELF AS TO WHETHER YOU UNDERSTAND THE TERMS DESCRIBED IN THIS LESSON. YOU WILL BE TESTED ON THESE TERMS IN YOUR UNIT TEST.

IF YOU FEEL THAT YOU DON'T UNDERSTAND THESE TERMS WELL ENOUGH, THEN READ THE LESSON MATERIAL AGAIN. BE SURE THAT YOU READ ALL THE EXAMPLES AND LOOK AT THE PICTURES THAT POP UP WHEN YOUR MOUSE ROLLS OVER THE HIGHLIGHTED WORDS. TRY TO FIND ALL OF THESE HIGHLIGHTED WORDS THAT CAUSE SOMETHING ELSE TO POP UP. THEN REDO THE ACTIVITY AND THE ASSIGNMENT. READ EACH POP UP MESSAGE AS IT IS DISPLAYED ON THE SCREEN.