[Chemistry Class Notes] Nonelectrolyte Pdf for Exam

A nonelectrolyte is a type of substance that does not ionize in either a molten state or in solution. These substances do not have a distinct ionized state. Due to their poor dissociation property, they are often bad conductors of electricity. Moreover, some of these nonelectrolytes often have an insulating effect when it comes to the conduction of electric current. Essentially a nonelectrolyte is a substance that does not break into ions when stirred into a solution. The substances with the opposite characteristics of nonelectrolytes are the electrolytes. An electrolyte readily dissociates when placed in an aqueous solution. These substances are, therefore, also good conductors of electricity. In this article, we will focus on nonelectrolyte chemistry.

Examples of Nonelectrolytes 

Nonelectrolytes are chemical compounds that do not ionize even when we dissolve them in a solution. Therefore, the solutions which contain a nonelectrolyte solute usually do not conduct electricity sufficiently. Some nonelectrolytes do not conduct any current. These compounds are generally brought together by covalent bonds rather than having ionic interactions.

Let us discuss two examples of nonelectrolytes. A very common nonelectrolyte would be sugar. If we talk specifically, glucose, which is a variety of sugar, is a good example of a nonelectrolyte. Glucose has a chemical formula of C6H12O6. Glucose readily dissolves in water but does not split into ions on dissolution. Therefore, we say that glucose is an example of a nonelectrolyte. This phenomenon is also the reason why solutions containing sugar do not conduct electricity. Salt, on the other hand, is a brilliant electrolyte. 

Another common example of a nonelectrolyte is an organic compound known as ethanol or ethyl alcohol. As with most organic compounds, ethanol is covalent and therefore does not ionize.

Distinguishing Electrolytes from Nonelectrolytes 

In the study of electrochemistry and when learning about the properties of nonelectrolyte chemistry, it is important that we can tell an electrolyte and a nonelectrolyte apart. The two sets of substances have different natures, they undergo different reactions, and they have different formations altogether. In this segment, we will separate a nonelectrolyte from an electrolyte with the help of two points. 

• The compounds which behave as electrolytes are always ionic. Their formation involves the coming together of ions. Electrolytes are held together by ionic bonds. When we dissolve such a substance in an aqueous solution or any polar solvent, we see the ionic bonds dissociating. On dissociation, we obtain cation and anion pairs, which then help to carry electricity. All ionic salts act as very strong electrolytes.

• In the case of nonelectrolytes, the formation of the compounds generally involves covalent bond formation. Covalent bonds are nonpolar, which means they do not have a charge separation. Due to the nonpolar property of these compounds, nonelectrolytes do not dissociate into a positive and negative part when stirred into a solvent. Due to this reason, nonelectrolytes do not conduct electricity. 

Solved Examples 

Q1. What Do You Call a Substance Which Does Not Dissociate in an Aqueous Solution or a Polar Solvent and Dissolves to Form a Non-conducting Solution?

1. electrolyte 

2. solute

3. nonelectrolyte 

4. conductor

Answer: A substance that does not dissociate in an aqueous solution or a polar solvent and dissolves to form a non-conducting solution is a nonelectrolyte.

Q2. What is a Nonvolatile Nonelectrolyte?

Answer: A nonvolatile nonelectrolyte is a molecule containing covalent bonds which does not:

• dissociate into a positive and negative half, and

• does not evaporate or sublime

when we add it to a solvent. These compounds or molecules have a special feature that helps in the quantitative analysis of these substances. The special property of these substances is such that their colligative concentrations match the value of their molar concentration, and this makes calculations with experimental data a lot easier. 

Q3. Do We Call Sodium Chloride an Electrolyte or a Nonelectrolyte?

Answer: Sodium chloride is an innately ionic compound. The structure of the compound is such that it ionizes very easily in any polar solvent. The formation of sodium chloride itself takes place by two ions coming together, namely, the sodium cation and the chloride anion. When placed in a solvent such as water, the compound separates into Na+ and Cl– ions. Therefore, sodium chloride is not a nonelectrolyte but rather a very strong electrolyte. 

Understanding Common Examples of Non-electrolytes

There are some commonly known non-electrolytes in chemistry. Let us understand with a few examples below.

The naphthalene balls, commonly known as mothballs fall under the category of non-electrolytes. The chemical composition of naphthalene balls is C10H8, so it contains 10 carbon atoms and 8 hydrogen atoms, like two benzene rings fused into each other, the chemical structure of naphthalene doesn’t allow it to ionize in water as it is non-polar in nature. Hence, it is a nonelectrolyte. In-room temperature, the naphthalene turns its state from solid to vapour. So, one doesn’t find any residue of it over time.

Benzene is a hydrocarbon compound with the chemical formula C6H6. It is a cyclic hydrocarbon chemical that is also non-polar in nature. Though we may not encounter benzene in our day-to-day life directly, it is still found in various products we use. Benzene is used in making plastics, resin, lubricants, rubber, dyes, and detergents. As benzene is non-polar, it doesn’t dissolve in polar solvents like water. Thus, there is no ionization seen, making it a non-electrolyte.

The chloroform is also known as trichloromethane with a chemical formula CHCl₃. It is a colorless and pungent-smelling liquid. The electric charge in trichloromethane is unevenly distributed, so it acts as a non-polar compound. Even though it dissociates in a polar solvent, it does so as molecules and not as ions. Thus, it is counted as a non-electrolyte.

Acetone is commonly named propanone. The chemical formula of this compound is (CH3)2CO. Acetone is a highly volatile liquid, has a characteristic odour, and is colourless.

Acetone is majorly used in nail polishes, paint thinners, and various other items. When the acetone is dissolved in water, the molecules of it don’t dissociate as ions, so they are counted as non-electrolytes.

Toluene is an organic compound with the chemical composition of C6H5CH3. It belongs to the aromatic hydrocarbon group. Toluene is the major ingredient in the production of permanent markers, paint thinners, glues as well as contact cement. Toluene is non-polar in nature, so when it is mixed with a polar solvent like water, it rather forms an emulsion and doesn’t dissociate into ions. Thus, toluene is classified as a non-electrolyte.

Commonly known as “liquor” in general terms, the chemical composition of ethyl alcohol is CH3CH2OH. Alcohol has covalent bonding. When water is mixed with alcohol, water molecules gather around it, but it doesn’t dissociate into ions due to the covalent bonding. Although, some of the covalent bonds do dissociate in water, like formic acid and carboxylic acids.

Thus, alcohol is known to be a non-electrolyte.