Physical Chemistry Answers

A CAPE Chemistry student sought to determine the solubility product, K_sp of calcium hydroxide by titrating saturated solution of Ca(OH)₂ against standardized hydrochloric acid solution, HCl. The saturated Ca(OH)₂ solution was filtered, to remove excess solute, and 25mL aliquots were titrated against 0.10M HCl solution using bromothymol blue indicator.

Calculate the concentration of Calcium Hydroxide. 

Use the equilibrium expression for the dissolution of Ca(OH)₂ to determine the concentration of Ca²⁺ and OH^–. [3]

a voltaic cell is designed using the following reaction Zn+2Ag -zn 2+ + 2 Ag determine the standard voltage Eo for this reaction ?

As a variation of the preceding problem explore the consequences of increasing the energy separation of the ψB and ψC orbitals (use SAB and SAC equal to 0 for this stage of the calculation). Are you justified in ignoring orbital ψC at any stage?

Show, if overlap is ignored, (a) that if a molecular orbital is expressed as a linear combination of two atomic orbitals in the form ψ = ψA cos θ + ψB sin θ, where θ is a parameter that varies between 0 and π, with ψA and ψB are orthogonal and normalized to 1, then ψ is also normalized to 1. (b) To what values of θ do the bonding and antibonding orbitals in a homonuclear diatomic molecule correspond?

Estimate the orbital energies to use in a calculation of the molecular orbitals of HBr. For data, see Tables 8B.4 and 8B.5. Take β = −1.00 eV.

A reasonably reliable conversion between the Mulliken and Pauling electronegativity scales is given by eqn 9D.4. Use Table 9D.1 in the Resource section to assess how good the conversion formula is for Period 3 elements.

Estimate the orbital energies to use in a calculation of the molecular orbitals of HCl. For data, see Tables 8B.4 and 8B.5. Take β = −1.00 eV.

A reasonably reliable conversion between the Mulliken and Pauling electronegativity scales is given by eqn 9D.4. Use Table 9D.1 in the Resource section to assess how good the conversion formula is for Period 2 elements.

The languages of valence-bond theory and molecular orbital theory are commonly combined when discussing unsaturated organic compounds. Construct the molecular orbital energy level diagrams of ethene on the basis that the molecule is formed from the appropriately hybridized CH2 or CH fragments.