Ionic Conductance and Mobility Concepts

The video tutorial explains ionic mobility, highlighting that smaller ions like lithium and sodium have lower mobility due to solvation. Despite being small and highly hydrated, H+ ions exhibit high mobility due to rapid proton transfer between water molecules. Similarly, OH- ions also show high mobility through proton exchange. The influence of temperature on ionic conductivity is discussed, with a focus on Walden's rule, which states that ionic conductance and viscosity are inversely related.

What is ionic mobility?

• The speed of an ion moving under a unit potential gradient

• The ability of an ion to dissolve in water

• The charge of an ion in a solution

• The size of an ion in a crystal lattice

Which ion is known for having very high ionic mobility?

• H+

• Li+

• Na+

• K+

Why do smaller ions like lithium and sodium have lower ionic mobility?

• They are less charged

• They are less reactive

• They are highly solvated, increasing their effective size

• They have a higher charge density

What is the primary reason for the high mobility of H+ ions in water?

• Their high charge

• The rapid transfer of protons through hydrogen bonds

• Their small size

• Their low solvation

How does the structure of ice affect the mobility of protons compared to water?

• Protons move slower in ice due to its rigid structure

• Protons dissolve in ice

• Protons move faster in ice because they can jump between fixed positions

• Protons are immobilized in ice

What mechanism explains the high mobility of OH- ions in water?

• Direct movement through the solution

• Exchange of protons between water and OH- ions

• Reduction of OH- ions

• Increase in temperature

According to Walden's rule, what is the relationship between ionic conductance and viscosity?

• They are equal

• They are unrelated

• They are inversely proportional

• They are directly proportional

How does temperature affect the viscosity of a liquid?

• Decreases viscosity

• Has no effect

• Makes it constant

• Increases viscosity

What is the temperature coefficient for H+ and OH- ions?

• 14 to 60%

• 5%

• 2% per degree rise

• 10%

What happens to ionic conductance as temperature increases?

• It fluctuates

• It remains constant

• It increases

• It decreases