Electrolytes and conductivity
To introduce the concept of electrolytes and conductivity, and to check electric current by means of an electric light bulb.
Cosa imparano gli studenti
La scienza alla base di questo esperimento
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.
Attrezzatura utilizzata
- 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
Sostanze chimiche e reagenti
- Acqua distillata
- 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
Note sulla sicurezza
- Be careful when using the power supply and conductive solutions: risk of electric shock.
Domande per gli studenti
- Note the current intensity by watching the brightness of the light bulb.
- Classify the electrolytes according to your observations.
Cosa aspettarsi
<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>
Smaltimento
Dispose of the solutions into the waste container.
Prova a fare questo esperimento in classe
Questo esperimento fa parte dell’ATP “ Mobile Lab ” — un laboratorio autonomo che trasforma una normale aula in un vero e proprio laboratorio scientifico, con oltre 200 esperimenti di fisica, chimica, biologia, robotica e ingegneria. “ Gali ”, il tutor basato sull’intelligenza artificiale integrato in ATP Connect, guida gli studenti in ogni fase e risponde alle loro domande direttamente al banco di lavoro.
Vedi il Mobile LabContatta il nostro team