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Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Iodine deficiency in diet is ____.


  1. Solutions of iodine in KI are used in treatment of Goiter.


  2. Goiter is enlargement of thyroid gland.


  3. Iodine deficiency in diet is known to cause Goiter.

  4. Iodine is necessary for normal functioning of the thyroid gland.
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation
Iodine is necessary for normal functioning of the thyroid gland.
Iodine deficiency in diet is known to cause Goiter.
Goiter is enlargement of thyroid gland.
Solutions of iodine in KI are used in treatment of Goiter.
Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Which of the following will displace the halogen from the solution of of halide
a $) Br _{2}$ added to an $NaCl$ solution
$\mathrm{b}) Cl _{2}$ added to a $KBr$ solution
$\mathrm{c}) Cl _{2}$ added to an $NaF$ solution
$\mathrm{d}) Br _{2}$ added to to a $KI$ solution
Find the correct answer :

  1. a, b, c

  2. b, c

  3. b, d

  4. all are correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$Br^{-}$ can reduce $Cl _{2}$ to $Cl^{-}$ $(E _{cell}=+ve)$

$I^{-}$ can reduce $Br _{2}$ to $Br^{-}$ $(E _{cell}=+ve)$

$E _{cell}=+ve$ in both case

$\therefore$ Reaction is feasible

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Iodine can be obtained from NaI solution by the action of:

  1. chlorine

  2. bromine

  3. soluble chloride

  4. soluble bromine
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

The iodine can be obtained by reacting chlorine or bromine by NaI. This is because the electronegativity of chlorine and bromine is more than the iodine and also the reactivity of chlorine and bromine is more than the iodine.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Which of the following is incorrect?

  1. iodine is a solid

  2. chlorine is insoluble in water

  3. iodine is more reactive than bromine

  4. bromine is more reactive than chlorine
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

Reactivity order:-
$F _2>Cl _2> Br _2>I _2$
Thus, chlorine is more reactive than bromine and bromine is more reactive than iodine.

Chlorine is soluble in water.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

In KI solution, $ I _2 $ readily dissolves and forms :

  1. $ I^{-}$
  2. $ KI _2 $
  3. $ KI _2^- $
  4. $ KI _3 $
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In KI solution, $I _2$ readily dissolves and forms $KI _3$ which contains polyhalide ion $I _3^-$


$KI + I _2  \rightarrow KI _3$

Due to this, iodine is partly soluble in water but highly soluble in the $KI$ solution.

So, the correct option is $D$

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Correct order of reactivity of halogens is:

  1. $I _2 > Br _2 > Cl _2 > F _2$
  2. $Br _2 > I _2 > Cl _2 > F _2$
  3. $Cl _2 > Br _2 > I _2 > F _2$
  4. $F _2 > Cl _2 > Br _2 > I _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The reactivity of halogens decreases with increase in atomic number of halogens. So the correct order of reactivity of halogens is $F _2 > Cl _2 > Br _2 > I _2.$

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Iodide of MilIon's base is :

  1. $HIO _3$
  2. $K _2Hgl _4$
  3. $NH _2HgO.HgI $
  4. $Hg(NH _2)I$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Iodide of MilIon's base is $\displaystyle NH _2HgO.HgI$
It is formed when Nessler's reagent (alkaline solution of $\displaystyle K _2[HgI _4]$) reacts with $NH _3$. 

Iodide of MilIon's base is a reddish brown ppt.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Which two of the following salts are used for preparing iodized salt?
$(i)   KIO _3$
$(ii)  KI$
$(iii)  I _2$
$(iv)  HI$

  1. $(i)$ and $(ii)$
  2. $(i)$ and $(iii)$
  3. $(ii)$ and $(iv)$
  4. $(iii)$ and $(iv)$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Iodised salt is table salt mixed with a small amount of various salts of the element iodine.
$KIO _3$ and $KI$ are used for preparing iodised salt.
Potassium iodate and potassium iodine is used in the iodized salt to prevent the iodine deficiency.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Iodine exists in which form in iodised salt.

  1. $I _2$
  2. $NaIO _3$
  3. $ICl$
  4. $IO^- _4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Iodised salt is table salt mixed with a minute amount of one of the four iodine containing salts of hydroiodic acid or iodic acid: potassium iodate or potassium iodine and sodium iodate or sodium iodide.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Assertion: Iodine is more soluble in water than in carbon tetrachloride.
Reason: Iodineis a polar compound.

  1. If both assertion and reason are true and the reason is a correct explanation of the assertion.

  2. If both assertion and reason are true but reason is not a correct explanation of the assertion.

  3. If the assertion is true but reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but the reason is true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Iodine is less soluble in water than in carbon tetrachloride. Iodine is a non polar compound.
Iodine, being a non-polar compound is more soluble in $CCl _4$ (non-polar compound) than in water because "like dissolve like". So both the assertion and reason are false.