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Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Which of the following has highest melting point?

  1. $SrF _{ 2 }$
  2. $BeF _{ 2 }$
  3. $BaF _{ 2 }$
  4. $MgF _{ 2 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The melting point of a compound depends on Vander walls force of attraction which increases as molecular size increases, in given compounds Sr atom has the largest size, so vanderwalls force of attraction will be greater in $SrF _2$ and it will have the highest melting point.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Which of the following statements is true?

  1. $\mathrm{B}\mathrm{r} _{2}$ is more reactive than $\mathrm{Cl} _{2}$
  2. $I _{2}$ is more reactive than $\mathrm{B}\mathrm{r} _{2}$
  3. $\mathrm{C}1 _{2}$ isinsoluble in water

  4. Iodine is a solid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Reactivity oder in halogen is:
$F _2>Cl _2>Br _2>I _2$

So option A and are incorrect.
$Cl _2$ is soluble  in water and $I _2$ is a solid (purple crystals) thus option D is correct.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Change in entropy is negative for:

  1. $Bromine (I) \rightarrow Bromine (g)$
  2. $C(s)+H _2O(g) \rightarrow CO(g)+H _2(g)$
  3. $N _2(g, 10 \ atm) \rightarrow N _2(g, 1 \ atm)$
  4. $Fe(at \ 400 \ K) \rightarrow Fe(at \ 300 \ K)$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When $Br(I)$ goes to to $Br(g)$ then stability of molecules increase. This leads us to negative entropy.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Which of the following properties of the elements chlorine,bromine and iodine increase with increasing atomic number?

  1. Ionization energy.

  2. Ionic radius.
  3. Bond energy of the molecule ${X _2}$.

  4. Enthalpy of vaporization.
Reveal answer Fill a bubble to check yourself
B,D Correct answer
Explanation

The ionization energies of halogens decrease on moving down the group.

Similarly the bond dissociation energies decrease from chlorine to bromine to iodine.

With increase in the atomic number, the atomic and ionic radii of hydrogen increases from fluorine to iodine.

Also, the melting points and the boiling points increase in the same order.

Hence, the enthalpy of vaporization also increases in the same order.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

The electron affinity values (in kJ $mol^{-1}$) of three halogens X, Y and Z are respectively$ -349, -333 $and $-325$.


 X, Y, and Z respectively are :

  1. $F _2, Cl _2, Br2$
  2. $Cl _2, F _2$ and $Br _2$
  3. $Cl _2, Br _2, F _2$
  4. $Br _2, Cl _2$ and $F _2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to the values electron affinity the  three halogens X, Y and Z are $Cl _2$,$F _2$ and $Br _2$

Hence option B is correct