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प्रश्न
Why are halogens coloured?
Why are all halogens coloured?
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उत्तर
Almost all halogens are coloured. This is because halogens absorb radiation in the visible region. This results in the excitation of valence electrons to a higher energy region. Since the amount of energy required for excitation differs for each halogen, each halogen displays a different colour.
संबंधित प्रश्न
Iodine exists as
- polar molecular solid
- ionic solid
- nonpolar molecular solid
- hydrogen bonded molecular solid
Fluorine is a stronger oxidising agent than chlorine. Why?
F2 has lower bond dissociation enthalpy than Cl2. Why?
Which halogen compound in the following pair will react faster in SN2 reaction CH3Br or CH3I.
Give two examples to show the anomalous behaviour of fluorine.
Write the reactions of F2 with water.
Arrange the following in the order of property indicated for the given set:
HF, HCl, HBr, HI - increasing acid strength.
Select the correct alternative from the choices given :
The correct order of increasing acidic strength of the oxoacids of chlorine is:
Which one has the lowest boiling point?
The set with the correct order of acidity is:
Reduction potentials of some ions are given below. Arrange them in decreasing order of oxidising power.
| Ion | \[\ce{CIO^{-}_{4}}\] | \[\ce{IO^{-}_{4}}\] | \[\ce{BrO^{-}_{4}}\] |
| Reduction potential EΘ/V |
EΘ = 1.19 V | EΘ = 1.65V | EΘ = 1.74 V |
Which of the following is isoelectronic pair?
Which of the following statements are true?
(i) Only type of interactions between particles of noble gases are due to weak dispersion forces.
(ii) Ionisation enthalpy of molecular oxygen is very close to that of xenon.
(iii) Hydrolysis of XeF6 is a redox reaction.
(iv) Xenon fluorides are not reactive.
Solubility of iodine in water may be increase by adding
Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI.
Statement II: As the size of the elements F, Cl, Br, and I increase down the group, the bond strength of HF, HCl, HBr, and HI decreases and so the acid strength increases.
In the light of the above statements, choose the correct answer from the options given below.
Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI.
Statement II: As the size of the elements F, Cl, Br, and I increase down the group, the bond strength of HF, HCl, HBr and HI decreases and so the acid strength increases.
In the light of the above statements, choose the correct answer from the options given below.
Write the name and formula of oxoacid of fluorine.
