Tag: chemical bonding and structure

Quizzes (8) Questions (141)

Questions Related to chemical bonding and structure

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Metallic bonding is explained by:

  1. electron sea model

  2. band model

  3. both A and B

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In contrast to electrons that participate in both ionic and covalent bonds, electrons that participate in metallic bonds delocalize, forming a sea of electrons around the positive nuclei of metals. The availability of "free" electrons contributes to metals being excellent conductors.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Which of the following bonds produces a solid that reflects light in the visible region and whose electrical conductivity decreases with temperature and has high melting point?

  1. Metallic bonding

  2. Ionic bonding

  3. Covalent bonding

  4. Van der Waals bonding
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metals (metallic bonds) have these physical properties- 


1) Metals reflect the photons of the visible spectrum (light) falling on their surface, thus metals are often silver-white or greyish with the characteristic specular reflection of metallic lustre.

2) The electrical conductivity of metals decreases with a rise in temperature.
3) Metals have a high melting point.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

A  4 : 1 mixture of helium and methane is contained in vessel at 10 bar pressure. Due to a hole in the vessel, the gas mixture leaks out. The composition of mixture effusing out initially is

  1. 8:1

  2. 8:5

  3. 1:8

  4. 5:8
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Graham's Law of Effusion, the rate of effusion is proportional to the mole fraction of the gas and inversely proportional to the square root of its molar mass. For a 4:1 mixture of He (mass 4) and CH4 (mass 16), the ratio of effusion rates is (4/sqrt(4)) : (1/sqrt(16)) = 2 : 0.25 = 8:1.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Which of the following properties are because of presence of metallic bonding in metal atoms :

  1. Electrical conductivity

  2. Malleability

  3. Ductility

  4. All of the above

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Many of the characteristic properties of metals are attributable to the non-localized or free-electron character of the valence electrons. This condition, for example, is responsible for the high electrical conductivity of metals. The valence electrons are always free to move when an electrical field is applied. The presence of the mobile valence electrons, as well as the nondirectionality of the binding force between metal ions, account for the malleability and ductility of most metals. When a metal is shaped or drawn, it does not fracture, because the ions in its crystal structure are quite easily displaced with respect to one another. Moreover, the nonlocalized valence electrons act as a buffer between the ions of like charge and thereby prevent them from coming together and generating strong repulsive forces that can cause the crystal to fracture.
Hence option D is correct.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Electron pool theory of metals can not explain which of the following characteristics of metals?

  1. Hardness

  2. Malleability

  3. Electrical conductivity

  4. Sonorousness
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electron Pool Theory. 

This theory states that each atom present in a metallic crystal loses all of its valence electrons. As a result, a "pool" of electrons is formed. It is believed that positively charged metal ions are held together by this "pool" of electrons.
It explains metallic luster, electricity conductivity, thermal conductivity, malleability and ductility.

It cannot explain hardness of the metal.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Metallic solids are solids made entirely of :

  1. one metallic element

  2. multiple metallic elements

  3. ionic bonds

  4. covalent bonds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metallic bonding arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a lattice of positively charged ions (cations). 

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

In metal solids, the _____________ electrons form a shared electron cloud.

  1. middle

  2. valence

  3. inner

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metallic bonding may be described as the sharing of free electrons among a lattice of positively charged metal ions. The structure of metallic bonds is very different from that of covalent and ionic bonds. While ionic bonds join metals to nonmetals, and covalent bonds join nonmetals to nonmetals, metallic bonds are responsible for the bonding between metal atoms. In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a sea of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions. The electrons then move freely throughout the space between the atomic nuclei.

Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

Attractive forces between metal ions and delocalized electrons can be weaken or overcome by :

  1. water

  2. pressure

  3. high temperature

  4. all of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Metallic bonding is the strong attraction between closely packed positive metal ions and a 'sea' of delocalised electrons. So,high energy is required to overcome this bond, hence high temperature can be used to weaken or overcome these attractive forces.