عنوان الموضوع : مساعدة فالانجلييييزية
مقدم من طرف منتديات العندليب

السلام عليكم
ممكن تعطوني تجارب علمية بسيطة مجربة من قبل نعملها فالكلاصة بلانجليزية وقاتلنا الاستاذة بلي هدا هو الفرض راني حاير من فضلكم سااااااااااااعدوني


>>>>> ردود الأعضـــــــــــــــــــاء على الموضوع <<<<<
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>>>> الرد الأول :

حاب نعاونك بصح ما فهمتش ؟؟؟؟؟؟؟؟؟؟؟؟؟؟

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>>>> الرد الثاني :

First, the material:
- Container
- Water
- Ground pepper
- Dishwashing

So in the container, you put water, then you sprinkle pepper
the water surface, you apply a little dishwashing liquid on your finger
and when you hit the water the pepper will be posted to the edges of
container.

Tips: In order to surprise and impress your friends do not show them the
dishwashing liquid. (Set quietly on your finger).
All experiments

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>>>> الرد الثالث :

التجربة بالعربية


أولا ، المواد :
-- الحاويات
-- المياه
-- الفلفل البري
-- جلي

حتى في حاوية، يمكنك وضع المياه، ثم يرش الفلفل
سطح الماء ، وتطبيق القليل من الماء في غسل الاطباق إصبعك
ومتى تصل المياه يتم نشر الفلفل على حواف
حاوية.

نصائح : من أجل مفاجأة وإثارة إعجاب أصدقائك لا تظهر لهم
سوائل غسل الاطباق. (تعيين بهدوء على إصبعك).
جميع التجارب

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>>>> الرد الرابع :

وهناك تجربة بسيطة
حرق قطعة خبز
وعندما يتفحم الخبز يكون دلالة على وجود الكربون فيه

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>>>> الرد الخامس :

بالانجليزية
Burn a piece of bread
When roasted bread be a sign of the presence of carbon which

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Sucking An Egg In A Bottle- Science Experiment

What You Need:
1 hard-boiled egg, peeled
1 long-necked bottle
3 matches

Demonstrates Science Category: Physics (Thermodynamics)
Ages: Elementary Science (Adult Assistance Required), Middle School Science (Adult Assistance Required), High School Science (Adult Assistance Recommended)

Caution: Experiment MUST be done with adult assistance and supervision!

I recommend these printable science project plans for K-12 for hundreds of great project blueprints and this step-by-step guide for doing an award winning science fair project. Also be sure to check out these fun science kits as a fast, simple way to get started on your science experiment.
What To Do:
1) Hard boil an egg and allow to cool. After the egg cools, peel off the ****l.
2) Place a long-necked bottle on your kitchen table (or any table free from flammable debris)
3) Have an adult light 3 matches and place in the bottle (all matches at once, not one at a time)
4) Quickly put the egg on top of the bottle opening



3 minutes



Demonstrates scientific principles:
The matches heats the air, which causes it to expand. When the matches extinguish, it causes the air to contract as it cools. A lower pressure is created within the bottle, than on the outside. The pressure outside the bottle causes the egg to get sucked into the bottle.
Heat causes most solids and liquids to expand, and cooling causes them to contract. Atoms or molecules within the solids vibrate more quickly with the increased heat. This causes the solid/liquid to become larges, and when cooled, become smaller.


How to Make Aspirin - Acetylsalicylic Acid - Introduction and History

Molecular Structure of Acetylsalicylic Acid or Aspirin
Dr. A.M. Helmenstine
Aspirin is the most widely used over-the-counter drug in the world. The average tablet contains about 325 milligrams of acetylsalicylic acid with an inert binding material such as starch. Aspirin is used to relieve pain, reduce inflammation, and lower fever. Aspirin originally was derived by boiling the bark of the white willow tree. Although the salicin in willow bark has analgesic properties, purified salicylic acid was bitter and irritating when taken orally. Salicylic acid was neutralized with sodium to produce sodium salicylate, which was better-tasting but still irritated the stomach. Salicylic acid could be modified to produce phenylsalicylate, which was better tasting and less irritating, but released the toxic substance phenol when ****bolized. Felix Hoffman and Arthur Eichengrün first synthesized the active ingredient in aspirin, acetylsalicylic acid, in 1893.

In this laboratory exercise, you can prepare aspirin (acetylsalicylic acid) from salicylic acid and acetic anhydride using the following reaction: salicylic acid (C7H6O3) + acetic anhydride (C4H6O3) --> acetylsalicylic acid (C9H8O4) + acetic acid (C2H4O2)

First gather the chemicals and equipment used to synthesize the aspirin:
Materials
  • 3.0 g salicylic acid
  • 6 mL acetic anhydride*
  • 5-8 drops of 85% phosphoric acid or concentrated sulfuric acid*
  • distilled water (about 50 mL)
  • 10 mL ethanol
  • 1% iron III chloride (optional, to test purity)

*Use extreme caution when handling these chemicals. Phosphoric or sulfuric acid and acetic anhydride can cause severe burns.
Equipment
  • filter paper (12.5 cm)
  • ring stand with funnel
  • two 400 mL beakers
  • 125 mL Erlenmeyer flask
  • 50 mL buret or measuring pipet
  • 10 mL and 50 mL graduated cylinder
  • fume hood, hot plate, balance
  • dropper
  • stirring rod
  • ice bath
    1. Accurately weigh 3.00 grams of salicylic acid and transfer to a dry Erlenmeyer flask. If you will be calculating actual and theoretical yield, be sure to record how much salicylic acid you actually measured.
    2. Add 6 mL of acetic anhydride and 5-8 drops of 85% phosphoric acid to the flask.
    3. Gently swirl the flask to mix the solution. Place the flask in a beaker of warm water for ~15 minutes.
    4. Add 20 drops of cold water dropwise to the warm solution to destroy the excess acetic anhydride.
    5. Add 20 mL of water to the flask. Set the flask in an ice bath to cool the mixture and speed crystallization.
    6. When the crystallization process appears complete, pour the mixture through a Buckner funnel.
    7. Apply suction filtration through the funnel and wash the crystals with a few milliliters of ice cold water. Be sure the water is near freezing to minimize loss of product.
    8. Perform a recrystallization to purify the product. Transfer the crystals to a beaker. Add 10 mL of ethanol. Stir and warm the beaker to dissolve the crystals.
    9. After the crystals have dissolved, add 25 mL of warm water to the alcohol solution. Cover the beaker. Crystals will reform as the solution cools. Once crystallization has started, set the beaker in an ice bath to complete the recrystallization.
    10. Pour the *******s of the beaker into a Buckner funnel and apply suction filtration.
    11. Remove the crystals to dry paper to remove excess water.
    12. Confirm you have acetylsalicylic acid by verifying a melting point of 135°C.

  • wash bottle

Here are some examples of follow-up activities and questions which may be asked upon synthesizing aspirin:

  • You can compare the actual and theoretical yield of acetylsalicylic acid based on the initial quantity of salicylic acid. Can you identify the limiting reactant in the synthesis?
  • You can compare the quality of the synthesized aspirin with commercial aspirin and salicylic acid. Add one drop of 1% iron III chloride to separate test tubes containing a few crystals of each substance. Observe the color: Pure aspirin would show no color, while salicylic acid or traces of it in impure aspirin will show a purple color.
  • Examine the aspirin crystals under a microscope. You should see white small-grained crystals with obvious repeating units.
  • Can you identify the functional groups in salicylic acid? Can you predict how these groups affect the properties of the molecule and how the body reacts to it? Salicylic acid has an -OH group (an alcohol) and a carboxyl group -COOH (an organic acid). The acid portion of the molecule is one of the factors that causes irritation in the stomach. In addition to irritation caused by acidity, aspirin causes stomach irritation by inhibiting the production of prostaglandins, hormones responsible for slowing gastric acid produc

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How to Make Aspirin - Acetylsalicylic Acid - More Follow-Up Questions


Here are some additional questions relating to aspirin synthesis:
  • Can you explain what happened to the -OH group in the salicylic acid when the acetic acid was added? The -OH group from the salicylic acid combined with the acetic acid, producing water and an ester group. Can you see what effect this had on the end product? This reduced the strength of the acid and made the aspirin easier to ingest.
  • Why do you think the aspirin was washed with distilled water? How did this affect the end product? How did this affect the actual product yield? Washing the aspirin removed most of the unreacted salicylic acid and acetic anhydride to yield a purer product. Some product was dissolved and lost in the washing process. Cold water was used to miminize dissolving the product.
  • How did the synthesis use different temperatures to affect solubility of aspirin? At higher temperatures (warm water), molecules have more kinetic energy and collide with each other more often to interact with water molecules, increasing the solubility of the aspirin. The ice bath slowed the molecules, allowing them to more easily stick together and "fall out" of solution or crystallize.