Home
Class 11
CHEMISTRY
Li^(+) ion is the smallest one among th...

`Li^(+)` ion is the smallest one among the ions of group- 1 elements. It would, therefore, be expected to have much higher ionic mobility and hence the solutions of lithium salts would be expected to have higher conductivity than that of solutions of cesium salts. However in reality, the reverse is observed. Explain.

Text Solution

Verified by Experts

Due to high charge density, very small `Li^(+)` ion gets much more hydrated compared to the large `Cs^(+)` ion. Thus, size of the hydrated lithium ion is much larger than that of the hydrated cesium ion. For this reason, the mobility of `Li^(+)` ion is much lower than that of `Cs^(+)` ion and consequently, the solutions of lithium salts has much lower conductivity than the solutions of cesium salts.
Promotional Banner

Topper's Solved these Questions

  • s-BLOCK ELEMENTS

    CHHAYA PUBLICATION|Exercise ENTRANCE QUESTION BANK|38 Videos

  • s-BLOCK ELEMENTS

    CHHAYA PUBLICATION|Exercise MCQ HOTSPOT (SINGLE CORRECT TYPE)|60 Videos

  • s-BLOCK ELEMENTS

    CHHAYA PUBLICATION|Exercise SOLVED NCERT EXERCISE|56 Videos

  • REDOX REACTIONS

    CHHAYA PUBLICATION|Exercise PRACTICE SET|4 Videos

  • SOME BASIC CONCEPTS OF CHEMISTRY

    CHHAYA PUBLICATION|Exercise PRACTICE SET|13 Videos

Similar Questions

Explore conceptually related problems

Which one of the following two acids will have a higher concentration of H_(3)O^(+) ions in their 0.1(M) aqueous solution- (1) HCl and (2) CH_(3)COOH ?

Alkali metal salts are water soluble and ionic in nature. Two factors such as lattice energy and hydration energy decide the extent of solubility. These two factors are opposing in nature solubility will be high if hydration energy is high. Higher will be the extent of hydration if size of the ion is smaller. Hydration of ions is exothermic process.Hydration energy also plays a role in deciding reducing power of alkali metals in solution. Identify the strongest reducing agent among alkali metals in solutions

The vlaue of van der waals constant 'a' for nitrogen gas is 1.37L^(2)*atm*mol^(-2) , but that for ammonia gas is 4.30L^(2)*atm*mol^(-2) . What is the reason for this large difference ? Which one of these two gases would you expect to have higher critical temperature?

Alkali metal salts are water soluble and ionic in nature. Two factors such as lattice energy and hydration energy decide the extent of solubility. These two factors are opposing in nature solubility will be high if hydration energy is high. Higher will be the extent of hydration if size of the ion is smaller. Hydration of ions is exothermic process.Hydration energy also plays a role in deciding reducing power of alkali metals in solution. Among the following the least soluble is

Knowledge Check

  • If a sparingly soluble salt is placed in water, after some time an equilibrium is established when the rate of dissolution of ions from the solid equals the rate of precipitation of ions from the saturated solution at a particular temperature. Thus, a dynamic equilibrium exists between the undissociated solid species and the dissolved ionic species ina saturated solution at a particular temperature. For example, in AgCl, we have the equilibrium AgCl iff Ag^+ (aq)+Cl(aq ) K_(eq) = ([Ag^+][Cl^-])/[AgCl] K_(eq)xx[AgCl]=[Ag^+][Cl^-]..........(A) K_(sp)(AgCl)=[Ag^+][Cl^-] Therefore [AgCl] is constant If there would not have been a saturated solution, then from equation (A), Keq. [AgCl] ne K_(sp) but K_(eq).[AgCl]=Q_(AgCl) where Q is ionic product. It implies that for a saturated solution,,br> Q=K_(sp) K_(sp) is temperature depended. When Q lt K_(sp) , then the solution is unsaturated and there will be no precipitate formation. When Q=K_(sp) , then solution will be saturated, no ppt, will be formed When Qgt K_(sp) , the solution will be supersaturated and there will be formation precipitate A solution is a mixture of 0.05 M NaCl and 0.05 M Nal. The concentration of iodide ion in the solution when AgCl just starts precipitating is equal to

    A
    `4xx10^-6 M`
    B
    `2xx10^-8 M`
    C
    `2xx10^-7 M`
    D
    `8xx10^-15 M`

  • If a sparingly soluble salt is placed in water, after some time an equilibrium is established when the rate of dissolution of ions from the solid equals the rate of precipitation of ions from the saturated solution at a particular temperature. Thus, a dynamic equilibrium exists between the undissociated solid species and the dissolved ionic species ina saturated solution at a particular temperature. For example, in AgCl, we have the equilibrium AgCl iff Ag^+(aq)+Cl(aq) K_(eq) = ([Ag^+][Cl^-])/[AgCl] K_(eq)xx[AgCl]=[Ag^+][Cl^-]..........(A) K_(sp)(AgCl)=[Ag^+][Cl^-] Therefore [AgCl] is constant If there would not have been a saturated solution, then from equation (A), Keq. [AgCl] ne K_(sp) but K_(eq).[AgCl]=Q_(AgCl) where Q is ionic product. It implies that for a saturated solution,,br> Q=K_(sp) K_(sp) is temperature depended. When Q lt K_(sp) , then the solution is unsaturated and there will be no precipitate formation. When Q=K_(sp) , then solution will be saturated, no ppt, will be formed When Q gt K_(sp) , the solution will be supersaturated and there will be formation precipitate Answer the following questions based on above passage: pH of a saturated solution of Ba(OH)_2 is 12. Hence K_(sp) of Ba(OH)_2 is

    A
    `5xx10^-7 M^3`
    B
    `5xx10^-4 M^2`
    C
    `1xx10^-6 M^3`
    D
    `4xx10^-6 M^3`
    • CHHAYA PUBLICATION-s-BLOCK ELEMENTS -HIGHER ORDER THINKING SKILL (HOTS) QUESTIONS
    1. Li^(+) ion is the smallest one among the ions of group- 1 elements. I...

      Text Solution

      |

    2. The E^(0) value for Cl2//Cl^(-) is + 1.36, for I2//I^(-) is +0.53V, fo...

      Text Solution

      |

    3. The alkali metals are obtained not by the electrolysis of the aqueous ...

      Text Solution

      |

    4. The alkali metals are paramagnetic but their salts are diamagnetic-why...

      Text Solution

      |

    5. Beryllium & magnesium do not give colour to flame whereas other alkali...

      Text Solution

      |

    6. E^(0)" for " M^(2+)(aq) + e to M(s) (where, M = Ca, Sr or Ba) is nearl...

      Text Solution

      |

    7. Both alkaline earth metals and their salts are diamagnetic in nature. ...

      Text Solution

      |

    8. Beryllium salts can never have more than 4 molecules of water of cryst...

      Text Solution

      |

    9. How can anhydrous magnesium chloride be prepared from magnesium chlori...

      Text Solution

      |

    10. Anhydrone is used as a drying agent - why?

      Text Solution

      |

    11. Which out of BeCl2 and CaCl2 would give acidic solution when dissolved...

      Text Solution

      |

    12. Li-salts are commonly hydrated while other alkali metal salts are usua...

      Text Solution

      |

    13. Although the abundance of Na and K in the earth's| crust are comparabl...

      Text Solution

      |

    14. When caustic soda solution is kept in a glass bottle, the inner surfac...

      Text Solution

      |

    15. 2LiOH overset("red hot")to Li2O + H2O, but 2NaOH overset("red hot")tox...

      Text Solution

      |

    16. LiH overset(Delta)toxx" but " 2NaH overset(Delta)to 2Na + H2uarr Expla...

      Text Solution

      |

    17. Discuss the roles of Na2O2KO2 and LiOH in the purification of air.

      Text Solution

      |

    18. Lithium forms monoxide while sodium forms peroxide in the presence of ...

      Text Solution

      |

    19. The second ionisation enthalpies of alkaline earth metals are much low...

      Text Solution

      |

    20. Explain why the compounds of beryllium are much more covalent than the...

      Text Solution

      |