Bonding in the Water Molecule

For example, we can construct hi and h2, two hybrid orbitals for describing the bonds in the water molecule, by taking the two combinations... 

FIGURE 3.1 (a) Internal vibrations of the bonds in the water molecule, (b) rotational motion of water, and (c) translation of the water molecule. 

The electrons which are important for the bonding in the water molecule are those in the valence shell of the oxygen atom 2s22p4. It is essential to explore the character of the 2s and 2p orbitals, and this is done by deciding how each orbital transforms with respect to the operations associated with each of the symmetry elements possessed by the water molecule. 

The bond energy and bond-dissociation energy are the same for the bond in a diatomic molecule but are different for a bond in a polyatomic molecule. For example, the bond-dissociation energy for the O—H bond in the water molecule (splitting H20 into H + OH) is 119.9 kcal/mole and that for the O—H bond in the OH radical is 101.2 kcal/mole. Their average, 110.6 kca.l/mole, is the O—H bond energy. 

As the second example of a triatomic molecule, we shall consider the bonding in the water molecule. Water in its ground state has an angular configuration in which the H—O—H angle is about 105°. 

The reason for the unusual behavior of water lies in the structure of the water molecule (Figure 1-1) and in the molecule s ability to form hydrogen bonds. In the water molecule the atoms are arranged at an angle... 

Another example discussed in more detail in this book (Chap. 11) is the formation of vinyl acetate from ethylene, acetic acid, and oxygen. This reaction is highly exothermic due to the strong and stable bonds in the water molecules. 

Recall from the discussion of the water molecule in Section 4.1 that oxygen has a greater attraction for electrons than does hydrogen, causing the O—H bonds in the water molecule to be polar. This phenomenon occurs in other bonds as well, and we will discuss the topic of polarity in detail in... 

Elements and compounds can undergo chemical processes (reactions), which rearrange, break, or form bonds between atoms. Substances can also change by physical processes, which may alter the observable characteristics of the substance, but do not rearrange the internal structures of any molecules. The chemical compound water, for example, can be split into the element hydrogen and oxygen by electricity. That is a chemical reaction, because bonds in the water molecules break, and... 

Fig. 2.4. Polarisation of the O—H-bonds in the water molecule and the net dipole moment of the molecule...

The 0—FI bonds in the water molecule are covalent bonds formed by electron sharing between the oxygen and hydrogen atoms. Flowever, the electrons of the bond are not... 

In hydrolysis, the H-OH bond in the water molecule splits and the reactions take place in the presence of the H and OH ions. For example, calcium carbide in water reacts to produce acetylene and calcium hydroxide in solution ... 

Explain the bonding m molecules such as BeH, BHj, CH and NHj in terms of the overlap of hydrogen Is orbitals with hybrid atomic orbitals formed on the central atom Compare valence bond and molecular orbital descriptions of the bonding in the water molecule... 

Because oxidadon-reduction reactions are already moving electrons between various reactants to form products, it is relatively easy to force electrons to move in the opposite direction by applying an external electrical potential. By contrast, in acid-base chemistry, the water formed as a product is very stable, and breaking the strong O—H bonds in the water molecule is difficult. Thus, it is not easy to reverse this type of reaction. 

The = 4 reverse micelle corresponds to 140 water molecules and 35 sodium counterions. MC simulations were carried out using the standard Metropolis sampling procedure. In addition to the displacement moves, rotation of the water molecules involved a rigid body rotation around one of the three coordinate axes chosen at random (Allen and Tildesley 1987). MC simulations typically consist of 160 to 200 million equilibration moves followed by 60 to 80 million moves, during which system properties were accumulated. MD was implemented using the SHAKE algorithm (Ryckaert et al. 1977), which is a constraint dynamics method in which the bonds in the water molecules are held rigid. 

B The heat is used to break the covalent bonds in the water molecules. 

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