Tag: chemistry

Questions Related to chemistry

$  { I } _{ 2 }C{ l } _{  6}$ i s formed by the following reaction:


       $  2IC{ l } _{  3}\rightleftharpoons {I  } _{2  }C{l } _{ 6 }  $

On the basis of the structure of $  {I } _{2  }C{l } _{ 6 }  $, find the number of atoms lying in one plane.

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. 4

  2. 6

  3. 8

  4. 10

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Correct Option: B

In NaOX , X cannot be

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. ${ F } _{ 2 }$

  2. ${ Cl } _{ 2 }$

  3. ${ Br } _{ 2 }$

  4. $I _{ 2 }$

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Correct Option: D

The strongest oxidising agent is :

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. ${ Cl }^{ -1 }$

  2. ${ F }^{ -1 }$

  3. $O^{ -2 }$

  4. $N^{ -3 }$

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Correct Option: B

The table shows some information about elements in Group VII of the Periodic Table. 

Name State at room temperature Colour
Chlorine Gas yellow-green
Bromine liquid brown
iodine ? ?
Astaine solid black

Which information about iodine completes the table?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. State - liquid, colour - black

  2. State - liquid, colour - green

  3. State - solid, colour - grey

  4. State - solid, colour - yellow

Show answer
Correct Option: D
Explanation:
$\text{D) State-solid,Colour-yellow}$
$\text{Iodine is solid at room temperature and appears yellow in low concentrat}$

Affinity for hydrogen is maximum for

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $\mathrm{F} _{2}$

  2. $ \mathrm{Cl} _{2}$

  3. $\mathrm{B}\mathrm{r} _{2}$

  4. $I _{2}$

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Correct Option: A
Explanation:

Fluorine $(F _2)$ is a halogen , which is a non-metal and has highest electronegativity, so it has maximum affinity for hydrogen. 

Which requires the highest energy for excitation?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. F

  2. Cl

  3. Br

  4. I

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Correct Option: A
Explanation:

Fluorine has a small size thus it has a high nuclear charge and its electrons are strongly attracted towards the nucleus. Thus it requires high energy for excitation. Among halogen atoms, fluorine requires the highest energy for excitation.

Halogens means:

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. ore forming elements

  2. sea salt products

  3. inert gases

  4. rare gases

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Correct Option: B
Explanation:

Sea salt $\to$ like $Mgcl _{2},\ MgBr _{2}$ have halogens.  $\therefore$  Halogens are sea salt products

Which of the following has seven valence electrons?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $Na^{+}$

  2. $Al$

  3. $F$

  4. $Ti$

  5. $B$

Show answer
Correct Option: C
Explanation:

We know that halogens have 7 electrons in their valence shell.

$F, Cl, Br, I$ are halogens.
Hence, option $C$ is correct.

Which of the following statement is wrong? In the reaction $2KCl{ O } _{ 3 }+{ I } _{ 2 }\rightarrow 2KI{ O } _{ 3 }+{ Cl } _{ 2 }$?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. ${ Cl } _{ 2 }$ is more reactive than $I _{ 2 }$

  2. When $KCl{ O } _{ 3 }$ reacts with $I _{ 2 }$, ${ Cl } _{ 2 }$ is liberated

  3. $KCl{ O } _{ 3 }+{ I } _{ 2 }$ is a redox reaction and $I _{ 2 }$ is oxidized

  4. In the above reaction, $I _{ 2 }$ is reduced

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Correct Option: D
Explanation:

the given reaction is

${ 2KClO } _{ 3 }+{ I } _{ 2 }\rightarrow { 2KIO } _{ 3 }+{ Cl } _{ 2 }$
in reactant,oxidation state of iodine in ${ I } _{ 2 }=0$
in product,oxidation state of iodine in${ IO } _{ 3 }^{ - }\quad $is 3
so,oxidation state of iodine change from 0 to5,so it is oxidlsed.

For electron affinity of halogens which of the following is correct?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $Br>F$

  2. $F>Cl$

  3. $Br>Cl$

  4. $F>I$

Show answer
Correct Option: D
Explanation:

  • Electron Gain Enthalpy is the energy released when one mole of an electron is added to gaseous atoms of an element. 
  • The correct order of Electron gain enthalpy of Fluorine family is,
$Cl>F>Br>I$
The reason for this is that the size of the fluorine atom is very small. So when an electron is added in the fluorine atom it will suffer more electronegativity as all the electrons will be very close to each other and hence the electron gain enthalpy of chlorine is more negative than that of fluorine.