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Electrolytes are the substance in electrochemistry which dissolved in water and dissociate cations and anions during the electrolysis. Acids, bases, and salts in the state of solution or fused state conduct electricity by the transfer of electrons are called electrolytes. The decomposition of electrolytes due to the passage of electricity is called electrolysis. The current usually enter or leaves the electrolytes through some rods or strips of metal is called an electrode.

Strong electrolyte examples

The extent or degree of dissociation of different electrolytes is different. Strong electrolytes dissociate completely and render the solution in water highly conducting are called strong electrolytes. All salts, mineral acids like sulfuric acid (H₂SO₄), nitric acid (HNO₃), hydrochloric acid (HCl), and bases like sodium hydroxide (NaOH) and potassium hydroxide (KOH) dissociate practically in water solution are called strong electrolytes. The conductance of such acids and bases is very high and called strong acids and bases.

Weak Electrolytes Examples

On other hand, there are many substances that dissociate only to a small extent in water solution. The solution of such electrolytes has very low conductance properties or power. Such substances are called weak electrolytes. The carboxylic acids, phenols, alcohols, and some inorganic acids like hydrocyanic acid (HCN), boric acid (H₃BO₃), and bases like ammonia (NH₃), amines are examples of weak electrolytes.

Electrical conductivity of solvents

This idea about strong and weak electrolytes is quantitative only. There are some electrolytes, such as trichloroacetic acid solution are exhibiting intermediate behavior. In deciding the nature of strong and weak electrolytes, we consider water solution as a solvent. It must be remembered that the nature of solvent plays an important role in the degree of dissociation of dissolved substances. Generally, the higher the dielectric constant of the solvent, the greater is the chance of dissociation. Besides the dielectric constant of the solvent, there are other factors like hydrogen bonding that play an important role to describe electrolytes.

Physical Chemistry Questions Answers

Study physical chemistry in many universities and the board has been restructured with a greater emphasis on the conceptual and theoretical methodology and the applications of underlying basic concepts and principals. Naturally, the students find themselves unduly constrained when they are forced to refer to various books or online chemistry course materials to collect the necessary reading materials. It is primarily to help the students. This website provides systematic and comprehensive coverage of the theory as well as of the illustration of application and questions answers.

Ideal gas question

The molecules in the bulk of the container surrounded by other molecules in a symmetrical manner. This molecule on the whole experiences no net force of attraction. Now consider the molecule near the side of the container, which is about to strike one of its sides. These molecules contributing to the total pressure of the gas. This side molecule experiences a net force of attraction towards the center of the container. This results in decreasing the velocity of the molecule. Thus the molecule does not contribute much force as an ideal gas molecule where there been no forces of attraction. Thus the pressure of a real gas would be smaller than the corresponding pressure of the ideal gas.

Given, a = 1.4 atm lit² mol^-2 and b = 0.04 lit mol^-1 using Van der Waals equation. What is the possible deviation from ideal gas law behavior?

Application of combined gas law

Answer: Combination of Boyle's and Charles's law, (P₁V₁)/T₁ = (P₂V₂)/T₂. Here, P₁ = 1 atm, V₁ = 2000 cm³, T₁ = 300K, P₂ = 2, T₂ = 600K. Therefore, V₂ = 2000 cm³

Question: One liter of a gas at 300 atm and 473 K compressed to a pressure of 600 atm and 273 K. The compressibility factors found from the curves are 1.072 and 1.375 respectively at the initial and final states. What is the final volume of the gas?

How do you measure the mass of the gas?

Question

At 273 K and under the pressure of 100 atm the compressibility factor of oxygen 0.97. Calculate the mass of oxygen necessary to fill a gas cylinder of 108.5 lit capacities under the given conditions.

Answer

T = 273 K, Z = 0.97 and P = 100 atm.

Compressibility factor, Z = PV/RT where V is molar volume.

The molar volume of oxygen
V_m = ZRT/P
= (0.97 × 0.082 × 273 K)/(100)
= 2.17 lit mol^-1

The mass of this molar volume will be equal to the molar mass of oxygen, which is 2.17 lit of oxygen equal to 32 gm.

Thus the mass of oxygen required to fill the gas cylinder 108.5 lit under the given condition

= 1600 gm
= 1.6 Kg

Question

Calculate the weight of oxygen necessary to fill up a cylinder of 5-liter capacity at 0⁰ C and 100-atmosphere pressure when the compressibility factor 0.96.

Answer

Number of moles (n) = g/M gm mol^-1 and Z = compressibility factor.

PV = Z × nRT or, n = PV/ZRT
∴ g/M = PV/ZRT or, g = PVM/ZRT
∴ Weight of oxygen = PVM/ZRT

= 744 gm

Van der Waals question answer

For n mole real gas, Van der Waals equation of state

Unit of a = atm lit² mol^-2

CGS unit of a
= dyne cm^-2 cm⁶ mol^-2
= dyne cm⁴ mol^-4

SI unit of a
= Newton m^-2 m⁶ mol^-2
= Newton m⁴ mol^-2

SI unit of b = m³ mol^-1

CGS unit of b = cm³ mol^-1

The dimension of a = [M L⁵ T^-2 mol^-1]

Dimension of b = [L³ mol^-1]

Question

What is the Boyle temperature of nitrogen gas if a = 1.4 atm lit² mol⁻² and b=0.04 lit mol⁻¹?

Answer

Boyle temperature, TB = a/Rb

∴ Boyle temperature for nitrogen gas
= 1.4/(0.082 × 0.04) K
= 427 K