Water bent shape

This determination of the molecular geometry of carbon dioxide and water also accounts for the fact that carbon dioxide does not possess a dipole and water has one, even though both are composed of polar covalent bonds. Carbon dioxide, because of its linear shape, has partial negative charges at both ends and a partial charge in the middle. To possess a dipole, one end of the molecule must have a positive charge and the other a negative end. Water, because of its bent shape, satisfies this requirement. Carbon dioxide does not. 

The discussion of the distortion of the water molecule from a linear to a bent shape allows a tentative general conclusion to be reached. This is that if a distortion of a molecule from a particular symmetry allows two MOs to mix, so that the lower occupied orbital is stabilized at the expense of the higher vacant orbital, such a distortion will occur and will confer stability on the distorted molecule. A gain of stability will only occur if the two orbitals concerned in the stabilization process are the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).. If both orbitals are doubly occupied, interaction between them does not lead to any change in stability. The generality of this conclusion is explored further in the next sections of this chapter and in Chapter 6. 

In a water molecule, the two hydrogen atoms bond to the oxgen atom at an angle of 109.5 degrees to form a bent-shaped molecule. This is because the bonding occurs with oxygen atom electrons in p orbitals. 

Without its bent-shaped molecule, water might be a gas at room temperature and ice might sink in water leaving our world uninhabitable. 

It is this bent shape of the water molecule that is responsible for its solvent power for so many salts. We speak of the water molecule as a dipole because its center of positive charge and negative charge are located at different points in space as shown ... 

In a water molecule, there are four electron pairs around the oxygen atom. Two of these pairs bond with the hydrogen. The electron pairs are arranged in a shape that is nearly tetrahedral. When you draw the molecule, however, you draw only the oxygen atom and the two hydrogen atoms. This is where the bent shape comes from, as you can see in Figure 3.28. 

The bent shape and polar bonds of a water molecule give it a permanent dipole. 

T, F Because of the bent shape of a water molecule, the dipole... 

The bent shape of the water molecule can be a source of confusion if you are not careful the oxygen atom in water is tetrahedrally coordinated, but the molecule itself has a shape defined by its atoms rather than its orbitals. The two hydrogen atoms are situated near the corners of a tetrahedron that is centered on the oxygen atom, but these three points define only a bent shape, not a complete tetrahedron. 

The water molecule will have a bent shape. 

Now consider a water molecule (H2O), which has two single covalent bonds and two lone pairs according to its Lewis structure. Although a water molecule has four electron pairs off the central atom, it is not tetrahedral because the two lone pairs occupy more space than do the paired electrons. The water molecule has a bent shape with a bond angle of 104.5°. 

The bent shape of a water molecule results in dipoles that do not cancel each other out. The molecule has a net polarity, with the oxygen end being partially negative and the hydrogen ends being partially positive. Refer to Table C-1 in Appendix C for a key to atom color conventions. 

B. H20]—Carbon dioxide and diatomic nitrogen have a linear shape. Methane has a tetrahedral shape. Water is the classic example of a bent shape. 

You saw earlier that the water molecule has a bent structure. The AEN of the O—H bond is 1.4 so the two O—H bonds in a water molecule are polar bonds. The oxygen end of the bond has a partial negative charge, while the hydrogen end of the bond has a partial positive charge. Because of its bent shape, the water molecule as a whole has a negative pole and a positive pole, as shown in Figure 9.22. 

The 0 — H bonds In a water molecule are polar. Because of water s bent shape, the hydrogen side of the water molecule has a positive charge, and the oxygen side has a negative charge. The arrows Indicate the directions in which electrons are pulled. 

Water, HzO, is a bent molecule, and ammonia, NH3, has the trigonal pyramid structure. Both have polar bonds that, because of their shapes, do not cancel the effect of each other. They combine to make the molecules polar. In the following figure, you can see that the bent shape of water and the trigonal pyramidal shape of ammonia cause both to be polar molecules. 

The H—O—H arrangement forms an angle, so the water molecule is bent. The combined effects of its bent shape and its polar bonds make water a polar molecule the O portion of the molecule is the partially negative pole, and the region midway between the H atoms is the partially positive pole (Figure 4.ID). 

You have seen that the water molecule has a bent shape and is therefore a polar molecule. This characteristic accounts for many of water s interesting properties. 

Water has two covalent bonds and two lone pairs. Repulsion between the lone pairs causes the angle to be 104.5°, less than both tetrahedral and trigonal pyramid. As a result, water molecules have a bent shape. 

A molecule of water has an angular or bent shape. The H—O — H bond angle in a molecule of water is 104.5°, an angle that is also quite close to the 109.5° bond angles of methane. 

Because F has a valence of 1, like H, it is reasonable to assume that the molecule OFg will assume a bent shape analogous to that of water (HOH). 

You have seen that the water molecule has a bent shape and therefore is a polar molecule. This accounts for many of water s interesting properties. What if the water molecule was linear How would this affect the properties of water, such as its surface tension, heat of vaporization, and vapor pressure How would life be different ... 

Molecular polarity. The combination of polar bonds and bent shape makes water a polar molecule the region near the O atom is partially negative, and the region between the H atoms is partially positive (Figure 4. ID). 

Because of polar bonds and a bent shape, the water molecule is polar, and water dissolves many ionic and covalent compounds. 

The water molecule has a bent shape. The two polar bonds are identical, so the bond dipoles are equal in magnitude. However, the bond dipoles are not directly opposite one another and therefore do not cancel each other. Consequently, the water molecule is a polar molecule (Figure 4.52) because it has an overall dipole moment. 

In the electron-dot formula of water, H2O, there are also four electron groups, which have minimal repulsion when the electron-group geometry is tetrahedral. However, in H2O, two of the electron groups are lone pairs of electrons. Because the shape of H2O is determined by the two H atoms bonded to the central O atom, the H2O molecule has a bent shape with a bond angle of 109°. Table 10.3 gives the molecular shapes for molecules with two, three, and four bonded atoms. 

In molecules with two or more electron groups, the shape, such as bent or trigonal pyramidal, determines whether or not the dipoles cancel. For example, we have seen that H2O has a bent shape. Thus, a water molecule is polar because the individual dipoles do not cancel. 

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