Factors Affecting Electrolytic Conductance and Working Procedure
The term electrolytic conductance is formed by connecting two important terms “electrolyte” and “conduction” or conductors”. It is important to first understand the meaning of these respective words. The electrolyte can be defined as a substance, which when dissolved in a polar solvent such as water produces electricity.
These electrolytes can only conduct electricity in the aqueous or molten form, and not in the solid-state. The process of dissolution of these substances in the solvent within the passage of an electric current is known as electrolysis. The second most important term for electrolytic conductance is known as “conductance” or “conductor”.
The study of electrolytic conduction is essential in developing foundation knowledge on more advanced topics such as electricity, batteries, or other electrical devices. Lastly, remember that any solution that enhances the movement of free-moving ions can be defined as electrolytic conductance. Different properties of this process can help in improving the level of dissociation of ions which improves the overall electrolytic conductance.
Electrolysis
Electrolysis is the process of decomposition of an electrolyte when the electricity passes through its aqueous solution or molten state. The apparatus where this process takes place is the Electrolytic cell.
What are Electrolytes?
When some substances dissolve in water, they undergo physical or chemical changes that generate ions in the solution which are called electrolytes. These electrolytes create electricity and can generate electricity only if they are in a liquid or molten state and not in their solid state. Substances that do not release ions when dissolved are known as non-electrolytes. If the chemical process generates 100% efficient ions then it is known as a strong electrolyte, but if it generates relatively weaker ions then it is known as a weak electrolyte.
Factors affecting Electrolytic Conductance
The Concentration of Ions in the Solution
The concentration of ions is the main factor that affects electrolytic conductance.
The conductance of the solution varies with the ion concentration. The conductivity of electrolytes will increase with the increase in the concentration of ions as there will be more charge carriers and the conductivity of electrolytes will be high, but if the concentration of ions is less then the conductivity of electrolyte will be less.
Type of Electrolyte
There are weak electrolytes and strong electrolytes, strong electrolytes get ionized completely in the solution whereas weak electrolytes do not. An example of a strong electrolyte is KNO3 and an example for a weak electrolyte is CH3COOH.
Temperature
Temperature is also one of the main factors as the ions should dissolve in the solution at a given temperature. So, at higher temperatures, the solubility is more.
Size of the Ion
The conductance of electrolytes depends on the size of the ion, the greater the size of the ion the lesser is the conductance. There you can say that Size of the ion is inversely proportional to the conductance of the ion.
Type of Solvent
The type of solvent is the fifth factor that affects electrolytic conductivity. Higher the polarity of the solvent type, the higher the conductivity.
Working Procedure of Electrolytic Conductance
Electrolyte conductance is the process that occurs in the presence of an electrolyte. The strength is transferred from cations and anions within side the electrolytic solution. The electrolytic conductance is characterized through equal conductance and is represented through the symbol “Λ”.
Λ = 1000 χ/c; where
Χ - particular conductance of the answer with the S.I unit ohm-1cm-1,
C - the concentration of the solution in grams equivalents per liter.
When the conductance reaches its maximum value, the solution has attained endless dilution, implying that every one molecule within side the electrolyte has dissolved into ions, producing conductance in cations and anions.
Furthermore, there are both strong and weak electrolytic conductors and the only one that completely dissociates is a powerful electrolytic conductor as they're made from strong bases and acids. Hydrochloric acid, sulphur dioxide, potassium iodide, and numerous inorganic salts, for example, are effective electrolytic conductors.
A weak electrolytic conductor is one that dissociates partly or insignificantly, permitting it to transmit energy to a restrained amount. A weak electrolytic conductor, in comparison to a strong electrolytic conductor, is made from weak bases and acids.
Calcium, potassium, sodium, magnesium, and chloride are a number of the most prevalent electrolytes. A few good examples of good conductors of electricity are Copper, silver, aluminium, and gold.
FAQs on Factors Affecting Electrolytic Conductance
1. What are the main factors that affect electrolytic conductance?
The primary factors that influence the electrolytic conductance of a solution include:
- Nature of the electrolyte: Whether the electrolyte is strong (dissociates completely) or weak (dissociates partially).
- Concentration of the solution: The number of ions per unit volume of the solvent.
- Temperature: Higher temperatures generally increase ionic mobility and conductance.
- Nature of the solvent: The polarity and viscosity of the solvent affect the dissociation and movement of ions.
- Size of the ions: The size of the ions and their degree of solvation influence their mobility in the solution.
2. What is the difference between a strong and a weak electrolyte?
A strong electrolyte is a substance that ionises almost completely when dissolved in a solvent like water. This results in a high concentration of mobile ions and, therefore, high electrolytic conductance. Examples include sodium chloride (NaCl) and hydrochloric acid (HCl). In contrast, a weak electrolyte dissociates only partially in solution, leading to a lower concentration of ions and lower conductance. Acetic acid (CH₃COOH) and ammonia (NH₃) are common examples of weak electrolytes.
3. How does the concentration of an electrolyte solution affect its conductance?
The effect of concentration is twofold. Conductivity (κ), which is the conductance of a unit volume of the solution, generally decreases with a decrease in concentration (dilution) because the number of ions per unit volume decreases. However, molar conductivity (Λm), which is the conductivity per mole of the electrolyte, increases with a decrease in concentration. This is because at infinite dilution, the inter-ionic attractions become negligible, allowing ions to move more freely and increasing the overall molar conductance.
4. Why does increasing the temperature generally increase electrolytic conductance?
Increasing the temperature of an electrolytic solution enhances its conductance for two main reasons. Firstly, it increases the kinetic energy of the ions, causing them to move faster towards the electrodes. Secondly, a higher temperature decreases the viscosity of the solvent and reduces the inter-ionic attractions between the solute particles. Both of these effects lead to greater ionic mobility and thus, a higher overall conductance.
5. What is an electrolytic cell and how does it work?
An electrolytic cell is an electrochemical device that uses external electrical energy to drive a non-spontaneous chemical reaction, a process known as electrolysis. It works by passing an electric current through an electrolyte. The cell consists of two electrodes: a negatively charged cathode and a positively charged anode, submerged in the electrolyte. Cations (positive ions) are attracted to the cathode where they undergo reduction, while anions (negative ions) move to the anode to undergo oxidation.
6. How do the factors affecting electrolytic conductance differ from those affecting metallic conductance?
The factors affecting electrolytic and metallic conductance are fundamentally different because their charge carriers differ. Here’s a comparison:
- Charge Carriers: In electrolytic conductors, charge is carried by ions moving through a solution. In metallic conductors, charge is carried by the flow of electrons.
- Effect of Temperature: Electrolytic conductance increases with temperature as it enhances ion mobility. Metallic conductance decreases with temperature because increased vibrations of metal kernels obstruct the flow of electrons.
- Chemical Change: Electrolytic conduction involves the decomposition of the substance (electrolysis). Metallic conduction involves no chemical change.
7. What role does the type of solvent play in electrolytic conductance?
The solvent plays a crucial role in determining electrolytic conductance. Solvents with a high dielectric constant and high polarity, such as water, are effective at weakening the electrostatic forces between ions, promoting greater dissociation of the electrolyte. Furthermore, a solvent with low viscosity allows ions to move more freely through it, resulting in higher conductance. Therefore, polar, low-viscosity solvents are ideal for electrolytic solutions.
8. Why does a larger ion size generally lead to lower electrolytic conductance?
It might seem counterintuitive, but the key factor is not just the bare ionic radius but the effective size of the ion in the solution, which includes its hydration or solvation sphere. Smaller ions often have a higher charge density, allowing them to attract and hold more solvent molecules, creating a larger effective radius. This larger, solvated ion experiences more frictional resistance as it moves through the solvent, resulting in lower ionic mobility and, consequently, lower electrolytic conductance.
9. What are some examples of strong and weak electrolytes as per the Class 12 Chemistry syllabus?
According to the CBSE syllabus for Class 12 Chemistry, common examples include:
- Strong Electrolytes: These dissociate completely. Examples are strong acids like Hydrochloric acid (HCl) and Sulphuric acid (H₂SO₄), strong bases like Sodium hydroxide (NaOH), and most salts like Potassium chloride (KCl) and Sodium chloride (NaCl).
- Weak Electrolytes: These dissociate partially. Examples are weak acids like Acetic acid (CH₃COOH) and Carbonic acid (H₂CO₃), and weak bases like Ammonium hydroxide (NH₄OH).
