Why Bond length of O-O is greater in H2O2 than O2F2?

Electronegativity of F is much more than hydrogen and also hybridization of oxygen atoms in of H₂O₂ and O₂F₂ both have (sp3) same and hence we can apply bent’s rule.

According bent’s rule more eletronegative atoms reduce % s-character (or increases % p-character vice versa) of those hybride orbital in which they attach. So in case of O₂F₂ % s-character of those hybride orbital decrease which have  flourine while % p-character increases in same way % s-character of  remaing hybride orbital inceases and p-character decreases hence its bond length also (bond length is directly proportional to % p-character) decreases.  hence O-O bond length in O₂F₂ is shorter thane H₂O₂.

“तलाश” मेरी क़लम से …

गुजरी है करीब से कई बहारे , किसी की महक से ये वजूद महका ही नहीँ ,

न जाने कहाँ है कौन है ओ । जिसकी तलाश मे दर बदर मै भटकता हूँ ,

कही तो ये तलाश ख़त्म होगीं , इस सफ़र की ,जो मंजिलें कहीँ खो गयी है ,

कभी तो मिलेंगी इसी इंतज़ार मे , चिलमन गिराये बैठा हूँ ॥ मै तेरी तलाश मे , हाँ तेरी तलाश मे , हाँ तेरी तलाश मे  ॥

(Written by: सुनील कुमार "सकल")

The activation energy of a reaction is 225 k Cal mol-1 and the value of rate constant at 40°C is 1.8 ×10^−5 s^−1 . Calculate the frequency factor, A.

SOLUTION:

Here, we are given that

Ea = 22.5 kcal mol-1 = 22500 cal mol-1

T = 40°C = 40 + 273 = 313 K

k = 1.8 × 10-5 sec-1

Substituting the values in the equation

log A = log (1.8) −5 + (15.7089)

log A = 10.9642

A = antilog (10.9642)

A = 9.208 × 101^0 collisions s^−1