IIT JAM
   Top Resources
Shweta Thakur posted an Question
June 14, 2020 • 00:45 am 30 points
  • IIT JAM
  • Chemistry (CY)

Sir oxide ,superoxide and peroxides stability and reactivity order

sir oxide ,superoxide and peroxides stability and reactivity order

3 Answer(s) Answer Now
  • 1 Likes
  • 6 Comments
  • 0 Shares
  • comment-profile-img>
    Dinesh khalmaniya 1

    Larger cations are stabilized by larger anions due to higher lattice energies.The anion sizes in increasing order are oxide < peroxide < superoxide, so lithium forms the most stable oxide, sodium the most stable peroxide and superoxide is the most stable form for the rest. The high charge density of lithium ion attracts the negative charge so strongly that it does not allow the oxide ion to take up another oxygen atom to form the peroxide ion. Sodium forms a peroxide as it forms a comparatively weaker positive field around it. K, Rb and Cs have weaker positive field around their cations and thus the oxide ion can take up two more oxygen atoms to form the superoxide ion.

  • comment-profile-img>
    Dinesh khalmaniya 1

    Oxides: Stability decreases down the group with lithium oxide the most stable. Peroxides: Increases and then decreases as we go from top to bottom in the group with sodium peroxide having the maximum stability. Superoxide: Stability increases down the group. Superoxides of K, Rb and Cs are most stable.

    eduncle-logo-app

    accept the answer if you get it

  • Suman Kumar best-answer

    As the size of alkali metal ion increases the stability of peroxides and super oxides increases. This is due to the stabilization of larger anions by larger cations. As we move from Li+ to Cs+ the size of the cations increases. Li+ is the smallest cation with strong positive field around it. Hence it combines with small anion called oxide ion (O-2) with strong negative field  and form Lithium oxide. Na+ ion is bigger than Li+ ion with less positive field around it combines with peroxide ion (O2-2) with less negative field and form sodium peroxide. K+, Rb+ and Cs+ ions are bigger in size with less positive field around them. Hence they can stabilize the bigger superoxide ion (O2-) with less negative field and form super oxides.

  • comment-profile-img>
    Lingareddy 1 Best Answer

    Oxides: Stability decreases down the group with lithium oxide the most stable. Peroxides: Increases and then decreases as we go from top to bottom in the group with sodium peroxide having the maximum stability. Superoxide: Stability increases down the group. Superoxides of K, Rb and Cs are most stable.

whatsapp-btn

Do You Want Better RANK in Your Exam?

Start Your Preparations with Eduncle’s FREE Study Material

  • Updated Syllabus, Paper Pattern & Full Exam Details
  • Sample Theory of Most Important Topic
  • Model Test Paper with Detailed Solutions
  • Last 5 Years Question Papers & Answers

Sign Up to Download FREE Study Material Worth Rs. 500/-