Electrolytes and conductivity
To introduce the concept of electrolytes and conductivity, and to check electric current by means of an electric light bulb.
ما يتعلمه الطلاب
الجانب العلمي وراء هذه التجربة
Electrolytes are substances that dissolve in water producing ions which conduct electrical current. Non-electrolytes are substances whose aqueous solutions do not contain ions and hence do not conduct an electric current.
Conductivity is the ability of a substance, solid, liquid or gas, to carry an electric current. Conductivity is measured in.
المعدات المستخدمة
- DC power supply
- Connecting wires, red — 2522.03-04
- Connecting wires, black — 2522.04-08
- Copper electrodes — 4716.21
- Crocodile clips — 2531.52
- Test cell covers — 4718.10
- Beaker 50 ml — 1118.15
- Lamp holder — 2505.50
المواد الكيميائية والمواد الكاشفة
- Distilled water
- Sucrose solution
- Hydrochloric acid solution 1 M — R:34-37 S:26-45
- Acetic acid solution 1 M — R:10-35 S:23-26-45
- Sodium chloride solution 1 M
- Sodium hydroxide solution 1 M — R:35 S:26-37/39-45
ملاحظات السلامة
- Be careful when using the power supply and conductive solutions: risk of electric shock.
أسئلة للطلاب
- Note the current intensity by watching the brightness of the light bulb.
- Classify the electrolytes according to your observations.
ما يمكن توقعه
<p>Electrolytes are classified either as strong electrolytes or weak electrolytes. Strong electrolytes when dissolved in water dissociate completely to produce ions.</p><p>Solutions of strong electrolytes are good conductors of electricity because they contain a relatively high concentration of ions.</p><p>Weak electrolytes are only partially converted to ions in aqueous solution. Ethanoic (acetic) acid, CH3CO2H, the active ingredient of vinegar, is a weak electrolyte.</p><p>Only about 1% of the dissolved ethanoic (acetic) acid molecules are converted to ions. The rest remain unchanged. Thus, a solution of a weak electrolyte contains a relatively low concentration of ions and its conductivity would be expected to be low.</p><p>Distilled water and sugar solutions do not conduct an electric current. Sugar is not an electrolyte.</p>
التخلص
Dispose of the solutions into the waste container.
قم بإجراء هذه التجربة في فصلك الدراسي
تُعد هذه التجربة جزءًا من برنامج «مختبر العلوم المتنقل» (ATP) Mobile Lab — وهو مختبر متكامل يحول الفصل الدراسي العادي إلى مختبر علوم فعال، ويضم أكثر من 200 تجربة في مجالات الفيزياء والكيمياء والبيولوجيا والروبوتات والهندسة. ويقوم « Gali » — وهو المعلم الذكي المدمج في موقع ATP Connect — بتوجيه الطلاب خلال كل خطوة والإجابة على أسئلتهم أثناء إجراء التجارب.
انظر Mobile Labتواصل مع فريقنا