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Saturday, February 29, 2020
Explain the significance of bond order. Can bond order be used for quantities comparisons of the strengths of chemical bonds?
Friday, February 28, 2020
Why is dimethylformamide (DMF) a useful solvent?
Why not peroxide effect observed in case of addition of HCl or HI with alkene but it observed with HBr only?
Sunday, February 23, 2020
Which of the following is a strongest acid among oxy acids of chlorine and why? "HClO, HClO2, HClO3, HClO4"
How does the thermal stability of oxyacids of chlorine increase with an increase in the oxidation state of chlorine atom ?
The thermal stability of oxy acids of chlorine increase on increasing of oxidation number of chlorine atom because on addition of additional oxygen atoms, the number of (pπ-dπ) π-bonds increase which provide extra stability to the molecules. Oxy acids of chlorine and their number of pπ-dπ bonds given as:
Thus the overall stability of oxy acids of chlorine are given as:
"HClO < HClO2 < HClO3 < HClO4"
What is the correct order of electronegativity of Cl atoms in HClO, HClO2, HClO3 and HClO4 ?
Why Chlorine (Cl2) bleaches a substance permanently but sulphuredioxide (SO2) does it temporarily?
Why Noble gases are mostly chemically inert?
The inertness to chemical reactivity of noble gases is attributed to the following reasons:
(1)The noble gases except helium (1s2) have completely filled ns2np6 electronic configuration in their valence shell.
(2) They have high ionisation enthalpy and more positive electron gain enthalpy.
Why Xenone (Xe) does not forms compounds such as xenone trifluoride (XeF3)and xenone pentafluoride (XeF5)?
By the promotion of one, two or three electrons from filled p-orbital to the vacant d-orbital in the valence shell, 2, 4 or 6 half filled orbitals are formed. Thus Xe can combine only with even number of fluorine and not odd.
Why Noble gases exhibit large positive values of electron gainenthalpy?
Since noble gases have stable electronic configurations, they have no tendency to accept the electron and therefore, have large positive values of electron gain enthalpy.
Why Noble gases have very low boiling points?
Noble gases being monoatomic have no interatomic forces except weak dispersion forces and therefore, they are liquefied at very low temperatures. Hence, they have low boiling points.