Shell model for NH 3 (H atomic #1, mass#1, N atomic #7, mass#14

Solutions

Expert Solution

Valence Shell Electron Pair Repulsion theory (VSEPR) is a set of rules whereby the chemist may predict the shape of an isolated molecule. It is based on the premise that groups of electrons surrounding a central atom repel each other, and that to minimize the overall energy of the molecule, these groups of electrons try to get as far apart as possible. Groups of electrons can refer to electrons that participate in a bond (single, double, or triple) to another atom, or to non-bonding electrons (e.g. lone pair electrons).

The ideal electronic symmetry of a molecule consisting of a central atom surrounded by a number of substituents (bonded atoms and non-bonding electrons) is characteristic of the total number of substituents, and is determined solely by geometric considerations the substituents are arranged so as to maximize the distances amongst them. VSEPR is useful for predicting the shape of a molecule when there are between 2 and 6 substituents around the central atom.

Ammonia also has four electron pairs and the coordination geometry of nitrogen is based upon a tetrahedral arrangement of electron pairs. There are just three bonded groups, therefore there is one lone pair. However since the lone pairs are 'invisible', the shape of ammonia is pyramidal.

Consider a bonding pair of electrons. The two electrons are located between two nuclei, and are attracted by both. A lone pair is different. It is necessarily only attracted to one nucleus and the consequence is that it adopts a position effectively closer to that one nucleus than the bonding pairs of electrons. This means that the effective solid angle occupied by a lone pair is greater than that occupied by a bond pair. Lone pairs demand greater angular room, and are located closer to their atoms than bond pairs. The consequence of this for ammonia is that the lone pair makes room for itself by pushing the three hydrogen atoms together a little and the H-N-H bond angles are slightly less (106.6

queen_honey_blossom answered 1 week ago

Next > < Previous

Related Solutions

Show that h(n) is a Lowpass filter, given that g(n) = (-1)nh(n) is a Highpass filter

Atomic Energy Levels. An atom in the second excited state (n = 3) of H is...

Atomic Energy Levels. An atom in the second excited state (n = 3) of H is just barely ionized when a photon strikes the atom—what is the wavelength of this photon? (Assume that all of the photon’s energy went into the atom.)

If an element has an atomic number of 7 and an atomic mass number of 15,...

If an element has an atomic number of 7 and an atomic mass number of 15, how many protons, neutrons, and electrons does it possess? a) 7 protons, 8 neutrons, and 7 electrons b) 7 protons, 8 neutrons, and 8 electrons c) 8 protons, 7 neutrons, and 8 electrons d) 15 protons, 8 neutrons, and 8 electrons

A compound contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and...

A compound contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

convergent or divergent infinity sigma n = 1 sqrt(n^5+ n^3 -7) / (n^3-n^2+n)

Prove that 3^n + 7^(n−1) ≡ 4 (mod 12) for all n ∈ N+.

calculate the number of atoms in 100.0g of mercury: Part 3: Average Mass: Atomic Mass =...

calculate the number of atoms in 100.0g of mercury: Part 3: Average Mass: Atomic Mass = (0.1687 X 198.968254) + (0.2310 X 199.968300) + (0.1318 X 200.970277) + (0.2986 X 201.970617) = 166.35 amu Isotope: 199Hg, 198.968254 amu, 16.87 % abundance Isotope: 200Hg, 199.968300 amu, 23.10 % abundance Isotope: 201Hg, 200.970277 amu, 13.18 % abundance Isotope: 202Hg, 201.970617 amu, 29.86 % abundance Part 4: Use the average mass calculated in Part 3 to calculate the number of atoms in 100.0g...

a) Prove that n 3 − 91n 2 − 7n − 14 = Ω(n 3 )....

a) Prove that n 3 − 91n 2 − 7n − 14 = Ω(n 3 ). Your answer must clearly specify the constants c and n0. b) Let g(n) = 27n 2 + 18n and let f(n) = 0.5n 2 − 100. Find positive constants n0, c1 and c2 such that c1f(n) ≤ g(n) ≤ c2f(n) for all n ≥ n0. Be sure to explain how you arrived at the constants.

Prove by induction that 14^n + 12^n −5^n is divisible by 7 for all n >0

Use proper calculus. (a) A conical shell has mass M, height h, and base radius R,...

Use proper calculus. (a) A conical shell has mass M, height h, and base radius R, Assume it is made from thin sheet of uniform thickness, Derive its center of mass and moment of inertia about its symmetry axis. (b) Derive the formula for the center of mass and the moment of inertia of a solid sphere, and then that of the moment of inertia about an axis tangent to the surface. (c) Derive the formula for the moment of...

Subjects