Conductance

Strong electrolytes These well-behaved systems include many simple salts such as NaCl, as well as all strong acids. The ? vs. vc plots closely follow the linear relation ? = ?? - b vc

The number of ions per cc decreases with dilution and therefore, specific conductance decreases with dilution.

The electronic conductance primarily depends on the number of valence electrons per atom, which allows for the conduction of electricity in materials. This is because the number of free electrons available for conduction directly influences the material's ability to carry an electric current.

Step 1: Understanding Kohlrausch's Law and its Application.
Kohlrausch's law of independent migration of ions states that the limiting molar conductivity of an electrolyte ( ) is the sum of the limiting ionic conductivities of its constituent ions. This law is particularly useful for determining the of weak electrolytes (like NH OH), which cannot be found by extrapolating a graph of vs. . We can calculate it using the values of strong electrolytes.
Step 2: Expressing the target in terms of ionic conductivities.
We want to find (NH OH). According to Kohlrausch's law: Our goal is to combine the values of strong electrolytes in a way that results in this expression.
Step 3: Analyzing the options.
Let's express the of the strong electrolytes in each option in terms of their ionic conductivities. We need to combine them to get . Consider option (B): (NH Cl) + (NaOH) - (NaCl)

• (NH Cl) =
• (NaOH) =
• (NaCl) =

Now, let's perform the combination: The and terms cancel out, leaving: This is exactly equal to (NH OH).
Step 4: Final Answer.
The correct combination is given in option (B).

Step 1: Key Formula for Relative Lowering of Vapour Pressure (RLVP).
According to Raoult's law, the relative lowering of vapour pressure of a solution containing a non-volatile solute is equal to the mole fraction of the solute ( ). Where: Step 2: Calculate the moles of solute (urea) and solvent (water).
Moles of urea (n ):

• Mass of urea = 18 g
• Molar mass of urea = 60 g/mol

Moles of water (n ):

• Mass of water = 100 g
• Molar mass of water (H O) = 18 g/mol

Step 3: Calculate the mole fraction of the solute (urea).
Step 4: Final Answer.
The relative lowering of vapour pressure is equal to the mole fraction of the solute, which is approximately 0.05.