Download App

Elements of Groups 16, 17 and 18 — Chemistry STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceChemistryElements of Groups 16, 17 and 184 Marks
Question
Explain the reactivity of group 16 elements towards halogens.
✓

Answer

  1. The group 16 elements with halogens form a large number of halides of the type $EX _2$ $E X_4$ and $EX _6$ where E is an element of the group and X is a halogen.
  2. The stability of the halides decreases in the order fluoride > chloride > bromide > iodide.
    ElementFluorideChloridesBromidesIodides
    S$S _2 F _2, SF _2, SF _4, SF _6$$S _2 Cl _2, SCl _2, SCl _4$$S _2 Br _2, SBr _2$$S _2 I _2$
    Se$Se _2 F _2, SeF _4, SeF _6$$Se _2 Cl _2, SeCl _2, SeCl _4$$SeBr _2, SeBr _4$-
    Te$TeF _4, TeF _6$$TeCl _2, TeCl _4$$TeBr _2, TeBr _4$$TeI _4$
  3. The hexahalides $SF _6, SeF _6, TeF _6$ are formed by direct combination. They are colourless gases. The hexahalides have $sp ^3 d ^2$ hybridisation and have an octahedral structure. $SF _6$ is exceptionally stable due to steric reasons.
  4. The tetrahalides $SF _4, SeF _4, TeF _4, TeCl _4$ have $sp ^3 d$ hybridisation and thus have a trigonal bipyramidal structure in which one of the equatorial positions is occupied by a lone pair of electrons. This geometry is also called see-saw geometry.
  5. The dihalides $SCl _2, SeCl _2, TeCl _2$ have $sp ^3$ and thus have a tetrahedral structures with two equatorial positions occupied by lone pairs.
  6. The monohalides $S _2 F _2, S _2 Cl _2, Se _2 Cl _2$ and $Se _2 Br _2$ are dimeric in nature. These halides have a tendency to undergo disproportionation. For example, $2 Se _2 Cl _2 \rightarrow SeCl _4+3 Se$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Answer the following in detail." from Elements of Groups 16, 17 and 18→Elements of Groups 16, 17 and 18 — all question types→Chemistry STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Answer the following

Explain the trends in atomic radii of d block elements.

→
Explain ring structure of glucose.
→
Complete the following reactions :
(i) $P _4 O _{10}+ H _2 O$
(ii) $C1 _2 O _7+ H _2 O$
(iii) $ZnO + HCl$
(iv) $ZnO + NaOH$
(v) $Al _2 O _3+ NaOH$.
→
Draw the structures of polymers formed from the following monomers
1. Adipic acid + Hexamethylenediamine
2. e – Aminocaproic acid + Glycine
→
A solution concentration is expressed in molarity and not in molality while considering osmotic pressure. Why ?
→
Consider a galvanic cell that uses the half reactions,
$2 H ^{+}{ }_{( aq )}+2 e ^{-} \rightarrow H _{( g )}$
$ Mg ^{2+}{ }_{( aq )}+2 e ^{-} \rightarrow Mg _{( s )}$
Write balanced equation for the cell reaction. Calculate $E _{\text {celll }} E _{\text {cell }}$ and $\Delta G ^0$ if concentrations are $1 M$ each and $P _{ H _2}=10 atm$
$E ^0 Mg ^{2+} / Mg =-2.37 V$
→
Define and explain the term molecularity of a reaction. Give examples.
###
Define the molecularity of a chemical reaction.
→
What current strength in amperes will be required to produce 2.4 g of Cu from $CuSO _4$ solution in 1 hour ? Molar mass of $Cu =63.5 g mol ^{-1}$.
→
Iron exhibits $+2$ and $+3$ oxidation states. Write their electronic configuration. Which will be more stable? Why?
→
Draw structure of salicylaldehyde.
→