Show that Acids, Bases, and Salts are Electrolytes

Our Objective 

To show that acids, bases, and salts are electrolytes.


The Theory


Acid, any substance that in water solution tastes sour, changes the colour of specific indicators (e.g., reddens blue litmus paper), reacts with some metals (e.g., iron) to liberate hydrogen, reacts with bases to form salts, and promotes specific chemical reactions (acid catalysis). Examples of acids include the inorganic substances known as the mineral acids—sulfuric, nitric, hydrochloric, and phosphoric acids—and the organic compounds belonging to the carboxylic acid, sulfonic acid, and phenol groups. Such substances contain one or more hydrogen atoms that, in solution, are released as positively charged hydrogen ions.


In chemistry, any substance in water solution is slippery to the touch, tastes bitter, changes the colour of indicators (e.g., turns red litmus paper blue), reacts with acids to form salts, and promotes specific chemical reactions (base catalysis). Examples of bases are the hydroxides of alkali and alkaline earth metals (sodium, calcium, etc.) and the water solutions of ammonia or its organic derivatives (amines). Such substances produce hydroxide ions (OH-) in water solutions.


In chemistry and physics, an electrolyte is a substance that conducts electric current by dissociating into positively and negatively charged particles known as ions, which migrate toward and are generally discharged at the negative and positive terminals (cathode and anode) of an electric circuit, respectively. Acids, bases, and salts are the most common electrolytes, which ionise when dissolved in solvents such as water or alcohol. Many salts, such as sodium chloride, function as electrolytes when melted in the absence of a solvent, while some, like silver iodide, are electrolytes even when solid.

When electrolytes dissolve in water, they separate into cations (plus-charged ions) and anions (minus-charged ions). We call this ionisation. Strong electrolytes ionise entirely (100%), whereas weak electrolytes only partially (1-10%). The main species in solution are ions for strong electrolytes, whereas, for weak electrolytes, the main species in solution is the un-ionized chemical itself.
Strong electrolytes are classified into strong acids, strong bases, and salts. (While salts are commonly referred to as ionic compounds, strong bases are also ionic compounds.) Weak electrolytes include weak acids and weak bases.

Electrical Conductivity

The movement of electrons plays a significant role in electrical conductivity. Metals are good electrical conductors because they allow electrons to travel across the whole substance. As a result, electrons flow through metals like a "sea of electrons." In comparison, distilled water is a poor electrical conductor because relatively little electricity travels through it. Strong electrolytes are highly ionised compounds. Strong electrolytes are acids and salts that ionise (dissociate or separate) in a solution. The ions conduct the electric charge through the solution, resulting in the generation of an electric current. If the current is significant, it will illuminate one or both LEDs on a conductivity metre.
Weak electrolytes are slightly ionised compounds. Because weak acids and bases do not completely dissociate in solution, they are classified as weak electrolytes. Non-electrolytes are substances that do not conduct an electric current. Non-electrolytes do not ionise and do not contain mobile ions. A conductivity meter's LEDs will not light up because no ions convey the electric current. 

Strong Electrolytes

Strong acid
Hydrochloric acid HCl(aq)
Hydrobromic acid HBr (aq)
Hydroiodic acid HI (aq)
Nitric acid HNO3 (aq)
Sulfuric acid H2SO4 (aq)
Perchloric acid HClO4 (aq)
Chloric acid HClO3 (aq)
Strong Base
Sodium hydroxide NaOH (aq)
Potassium hydroxide KOH (aq)
Calcium hydroxide Ca(OH)2 (aq)
Barium hydroxide Ba(OH)2(aq)
Soluble Salts
Sodium chloride NaCl(aq)
Potassium carbonate K2CO3K2CO3 (aq)
Copper (II) sulfate CuSO4CuSO4 (aq)

Weak Electrolytes

Weak Acids
Acetic acid HC2H3O2 (aq)
Carbonic acid H2CO3 (aq)
Citric acid C6H8O7 (aq)
Phosphoric acid H3PO4 (aq)
Weak Base
Ammonia NH3(aq)
Ammonium hydroxide NH4OH (aq)
Magnesium hydroxide Mg(OH)2(aq)
Slightly Soluble Salts
Silver chloride AgCl (s)
Calcium carbonate CaCO3 (s)
Barium sulfate BaSO4 (s)
Non Electrolytes
Distilled water H2O (l)
Methanol CH3OH(aq)


Liquids such as vegetable oil and coconut oil are poor conductors of electricity. Distilled water is also a poor conductor of electricity, and ordinary drinking water is a good conductor of electricity. Because lemon juice is acidic, it also conducts electricity.


Learning Outcomes 

  • Students will be able to understand the conductivity of different salts.
  • Students will be able to understand why deionised water does not conduct electricity.
  • The students will learn the concept of electrolytes.