Tag: p- block elements-ii

Questions Related to p- block elements-ii

The electro valency theory explains that atoms are held together by an attractive force.

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

  1. True

  2. False

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Correct Option: A
Explanation:

Electrovalency theory (valence band theory) explains two atoms that have an unpaired electron in their orbitals can overlap to give rise to chemical bond and chemical bond nothing but an attractive force between two atoms.

Arrange the following atoms in the order of increasing atomic radius.
F, Cl, C, O

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

  1. F, Cl, O, C

  2. C, O, F,Cl

  3. O, C, F, Cl

  4. F, O, C, Cl

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Correct Option: D
Explanation:

As we move along a period from left to right, number of proton increases and valence shell remains same, so, radius of atom decreases.
Also, as we move down the group, number of valence shell increases, so, size of atom increases so order of radii is F < O < C < CI.

Sea weeds are an important source of :

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

  1. Iron

  2. Chlorine

  3. Iodine

  4. Bromine

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Correct Option: C
Explanation:

Iodine is a component of almost every living plant and animal. No standard measurements of iodine in food exist because iodine concentrations vary across the world. In general, foods from the sea contain the most iodine, followed by animal foods, then plant foods. Of all foods, seaweed (like kelp), is the most well known and reliable source of natural iodine. Egg and dairy products can also be good sources.

Which is the most active element among folllowing?

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

  1. Chlorine

  2. Oxygen

  3. Sulfur

  4. Fluorine

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Correct Option: D
Explanation:

Most active element is Fluorine. The reduction potential of fluorine is very high. Hence, it is extremely reactive in nature. Also F-F bond energy is low (38 kcal/mol). The valence shell electron configuration of fluorine $2s^22p^5$  indicates that it has very strong tendency to take up one electron to attain stable noble gas configuration. Hence, it has high reactivity.

Which of the following is correct?

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

  1. Iodine is solid

  2. Chlorine is insoluble in water.

  3. Iodine is more reactive than bromine.

  4. Bromine is more reactive than chlorine.

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Correct Option: A
Explanation:

The reason is that the attractive forces between the molecules of these elements increase from top to bottom of the Group.

In iodine, the electrons are so far from the nuclei that the electron clouds can easily distort. The London dispersion forces are strong. So the Iodine is solid.

Hence option A is correct.

Formula of Freon is:

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

  1. $CCl _2F _2$

  2. $COCl _2$

  3. $SO _2Cl _2$

  4. none of these

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Correct Option: A
Explanation:

$CCl _2F _2$ is called as freons or chloro floro carbons.

Hence option A is correct.

Have you ever noticed the fact that two siblings can have different personalities? Even though two people may be members of the same family, it does mean that they will behave in similar ways.
The same thing can be said about elements in a group ("family") on the periodic table. For example, fluorine and iodine are members of the halogen family, but their physical properties are different, as shown in the table below.

Element Melting Point $(^{\circ}C)$ Boiling Point $(^{\circ}C)$
Fluorine $-220$ $-188$
Iodine $+118$ $+184$

Which of the following is the BEST explanation for these differences in melting and boiling point?

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

  1. Fluorine has a higher value for electronegativity than iodine.

  2. The covalent bond in the fluorine molecule is stronger than the covalent bond in the iodine molecule.

  3. Iodine molecules are larger and more polarizable than fluorine molecules.

  4. Fluorine is a nonpolar molecule, but iodine is a polar molecule.

Show answer
Correct Option: C
Explanation:

As we move down the group of halogens the size of elements increases thereby increasing the Van der Waal forces; hence boiling and melting point of Iodine is more than Fluorine molecule.

Which is soluble in water :

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

  1. AgCl

  2. AgBr

  3. AgI

  4. AgF

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Correct Option: D
Explanation:

Ionic compounds are soluble in water
In AgF  $F^-$ is small onion with high charge density so less polarisation and less covalent character in the whole group of Ag holdies.  AgF is most Ionic in nature.

Group 16 elements have a lower value of first ionization enthalpy as compared to group 15 elements because:

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. half filled p-orbitals in group 15 elements are more stable

  2. group 16 elements have smaller size than group 15 elements

  3. group 16 elements contain double bond while group 15 elements have a triple bond

  4. group 16 elements have more number of electrons in p-orbitals

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Correct Option: A
Explanation:

Group 16 elements have a lower value of first ionization enthalpy as compared to group 15 elements. As group 15 elements have half filled p-orbital due to which group 15 have got extra stability.

_______ group elements are known as chalcogens.

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. VIA

  2. VA

  3. Zero

  4. None of these

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Correct Option: A
Explanation:

VIA group or Group 16 elements belong to the oxygen family are also called chalcogens. The name is derived from the Greek word 'chalcos', which means 'ore' and 'gen', which means 'formation'.