Tag: group 17

Questions Related to group 17

Treatment of the dry solid _____ with a mild oxidizing agent produces a purple solid.

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

  1. $N _{2}$

  2. $KI$

  3. $CCl _{4}$

  4. $AgNO _{3}$

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Correct Option: B
Explanation:

An oxidising agent would displace iodine from potassium iodide. When iodine gets removed, free iodine appears purple in colour.

Statement I : The physical state of halogen molecules may be solids, liquids or gases at room temperature.
Statement 2 : The halogen molecules are considered as nonpolar and by increasing mass the dispersion forces between them increases.

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

  1. true, true, correct explanation

  2. true, true, not correct explanation

  3. true, false

  4. false, true

Show answer
Correct Option: A
Explanation:

Statement I : The physical state of halogen molecules may be solids, liquids or gases at room temperature.
Statement 2 : The halogen molecules are considered as nonpolar and by increasing mass the dispersion forces between them increases. With increase in the dispersion forces, the state changes from gas (fluorine and chlorine) to liquid (bromine) to solid (iodine).

The colour of chlorine gas is:

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

  1. red

  2. purple

  3. orange

  4. green

  5. blue

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Correct Option: D
Explanation:

Chlorine is a greenish-yellow gas. As we go down the group, the colour of halogens gets darker. Fluorine is pale-yellow in colour, chlorine is greenish-yellow. Bromine is red-brown and iodine is purple.

The halogen with the smallest covalent radius is:

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

  1. $I$

  2. $Cl$

  3. $Br$

  4. $F$

Show answer
Correct Option: D
Explanation:

The halogen with the smallest covalent radius is fluorine.
The halogen with the largest covalent radius is iodine.
The correct order of covalent radii among halogen is fluorine < chlorine <  bromine < iodine.

The bond energies of $F _{2}, Cl _{2}, Br _{2}$, and $I _{2}$ are 155 kJ $mol^{-1}, \ $244 kJ $mol^{-1}$, 193 kJ $mol^{-1}$ and 151 kJ $mol^{-1}$ respectively. The weakest bond will be in:

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

  1. $Br _{2}$

  2. $Cl _{2}$

  3. $F _{2}$

  4. $I _{2}$

Show answer
Correct Option: D
Explanation:

Since the bond energy of $I _2$ is least, it's bond will be weakest.

Which of the following family exist as diatomic molecules at room temperature?

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

  1. Alkali metals

  2. Alkaline earth metals

  3. Noble gases

  4. Halogens

  5. Transition metals

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Correct Option: D
Explanation:

Halogens exist as diatomic molecules at room temperature. The valence shell electronic configuration of halogens is  $\displaystyle ns^2 np^5$.  Two halogen atoms share one electron each to form diatomic molecule in which each halogen atom has completed its octet.

The compound IF$ 7$ is named as ________.

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

  1. iodine heptafluorine

  2. iodine septafluoride

  3. iodine fluoride

  4. none of these

Show answer
Correct Option: C
Explanation:

$IF _7$ is named as Iodine (VII) Flouride. Because the halogen of larger size give electron pair and the halogen of small size which has high electronegativity accepts a lone pair of electrons. So suffix '-ide' is added to halogen of small size.

Statement 1 : Elemental iodine has a higher boiling point than elemental bromine.
Statement 2 : Iodine forms stronger covalent bonds than bromine.

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

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not  the correct explanation of Statement 1.

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is  correct.

  5. Both the Statement 1 and Statement 2 are not correct.

Show answer
Correct Option: C
Explanation:

Statement 1: Elemental iodine has a higher boiling point than the elemental bromine because of the higher molecular mass of $I _2$ than the $Br _2$.
Statement 2: Iodine does not form stronger covalent bonds than $Br$ because size of iodine is larger due to which the bond becomes longer in length and longer bond is weaker, hence, forms weaker covalent bond.

Statement 1 : Bromine has a higher boiling point than chlorine.
Statement 2 : Bromine has stronger dispersion forces than chlorine.

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

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is correct.

  5. Both the Statement 1 and Statement 2 are not correct.

Show answer
Correct Option: A
Explanation:

Statement 1 : Bromine has a higher boiling point than chlorine. This is due to the fact that the Bromine has higher , molar mass than the Chlorine.
Statement 2:
Dispersion forces are present between all molecules, whether they are polar or nonpolar.
Larger and heavier atoms and molecules $(Br)$ exhibit stronger dispersion forces than smaller and lighter ones $ (Cl)$
In a larger atom or molecule, the valence electrons are, on average, farther from the nuclei than in a smaller atom or molecule. They are less tightly held and can more easily form temporary dipoles.
The ease with which the electron distribution around an atom or molecule can be distorted is called the polarizability.
London dispersion forces tend to be:
1. stronger between molecules that are easily polarized.
2. weaker between molecules that are not easily polarized.

In short "The more electrons a molecule has, the stronger the London dispersion forcesare. For example, bromine, Br2, has more electrons than chlorine, Cl2, sobromine will have stronger London dispersion forces than chlorine, resulting in a higher boiling point for bromine, 59 oC, compared to chlorine, –35 oC."

The solubility of $KCl$ is relatively more in (where D in dielectric constant):

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

  1. $C _6II _6 (D = 0)$

  2. $(CH _3) _2CO (D = 2)$

  3. $CH _3OH(D= 32)$

  4. $CCl _4 (D = 0)$

Show answer
Correct Option: C