Water electron geometry

Eor example, water (H2O) has two bonded and two lone pair valence electrons about the central atom, oxygen. Its electronic geometry, determined by four total groups, is tetrahedral, and its molecular geometry (meaning the El-O-El shape) is bent. Similarly, the NEl3 molecule has three... 

Choose the answer which best denotes the electronic orientation (electronic geometry) of the water molecule. 

The answer is D. This question is a bit tricky. Many students will quickly select angular as the answer. But you have to be careful. The question is not asking for the molecular geometry of water. It is actually asking for the electronic orientation or electronic geometry of water which is tetrahedral. The four electron pairs (two bonded pairs and two lone pairs) of the water molecule result in a tetrahedral geometry. Moreover, Choices A and B are essentially the same. If one is not correct, the other cannot be correct either. 

Next, let us consider an example where the electron and molecular geometries are different, such as that which occurs for H2O. The hybridization of the O atom in the water molecule is sp because the electron geometry around the central atom... 

Valence bond model applied to the water molecule. The sp hybridization of the O atom is dictated by the tetrahedral electron geometry of the molecule. Two of the sp hybrid orbitals are used to form bonds with the H atoms, while the other two sp hybrids contain the two lone pairs. 

Anick DJ (2003) Application of database methods to the prediction of B3LYP-optimized polyhedral water cluster geometries and electronic energies. J Chem Phys 119 12442-12456... 

Both water and ammonia have four groups attached to their central atom and therefore both possess a tetrahedral electronic (or VSF PR) geometry. However, H20 has two unshared electron pairs while NH3 only has one, producing a larger dipole moment for H,0. 

This chapter and the next describe chemical bonding. First, we explore the interactions among electrons and nuclei that account for bond formation. Then we show how atoms are connected together in simple molecules such as water (H2 O). We show how these connections lead to a number of characteristic molecular geometries, hi Chapter fO, we discuss more elaborate aspects of bonding that account for the properties of materials as diverse as deoxyribonucleic acid (DNA) and transistors. 

Start with water, which is essential for life as we know it. If the water molecule were linear rather than bent, it would lack the properties that life-forms require. Linear water would not be polar and would be a gas like carbon dioxide. Why is water bent Its four electron pairs adopt tetrahedral geometry, putting lone pairs at two vertices of a tetrahedron and hydrogen atoms at the other two vertices. 

Five-coordinate Ni111 complexes (89) have been prepared by oxidation of the square planar Ni11 precursor complexes [Ni(L)X] with either X2 or CuX2, and the crystal structure of the iodo derivative has been determined. The geometry at Ni is best described as square pyramidal, with the Ni atom displaced approximately 0.34 A out of the basal plane towards the apical I atom. EPR confirms the Ni111 oxidation state, in which the unpaired electron of the low-spin d1 system is situated in the dz2 orbital.308,309 In aqueous solution full dissociation of both X anions occurs, while in acetone solution dissociation is not significant. The redox couple [Nin NCN (H20)]+/ [Ni111 NCN (H20)ra]2+ in water is +0.14V (vs. SCE). 

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