Physical Chemistry Answers

Use an appropriate semi-empirical method to compute the equilibrium bond lengths and standard enthalpies of formation of (a) ethanol, (b) 1,4-dichlorobenzene. Compare to experimental values and suggest reasons for any discrepancies.

Set up the secular determinants for cyclobutadiene, benzene, and cyclooctatetraene and diagonalize them by using mathematical software. Use your results to show that the π molecular orbitals of monocyclic polyenes with an even number of carbon atoms follow a pattern in which:

• The π molecular orbitals of lowest and highest energy are non-degenerate.

• The remaining π molecular orbitals exist as degenerate pairs.

Suppose that a molecular orbital of a heteronuclear diatomic molecule is built from the orbital basis ψA, ψB, and ψC, where ψB and ψC are both on one atom (they can be envisaged as F2s and F2p in HF, for instance). Set up the secular equations for the optimum values of the coefficients and set up the corresponding secular determinant.

Predict the electron configurations of (i) the allyl radical, ⋅CH2CHCH2, (ii) the cyclobutadiene cation C4H4+. Estimate the π-electron binding energy in each case.

balloon can have a maximum volume of 3m3 before or bursts.iy is filled with helium at sea level and 30°C to have a volume of 0,5m3.when it finally bursts it reaches a height where the atmospheric pressure is equal to 11 kPa Calculate the temperature in °C when the Balloon bursts

What is an application of physical chemistry in the process of homeostasis

The Haber process was one of the most crucial breakthroughs in chemical science resulting from research aimed to avoid widespread famine at a time of massive population growth. The reaction conditions are optimal at 400  C, at 200 atmospheres of pressure, in the presence of a catalyst. If the partial pressure of N2(g) is 43.5 atm and H2(g) is 87.0 atm.,

N2(g) + 3H2(g) <-->  2NH3(g)

What is Kp for this reaction at this temperature?  (enter the answer as a decimal to four significant figures)

Examine whether occupation of the bonding orbital in the H2+ molecule-ion by one electron has a greater or lesser bonding effect than occupation of the antibonding orbital by one electron. Is your conclusion true at all internuclear separations?

Suppose that a molecular orbital has the (unnormalized) form 0.145A + 0.844B. Find a linear combination of the orbitals A and B that is orthogonal to this combination and determine the normalization constants of both combinations using S = 0.250.