what are some of the possible impurities in the preparation of tetraphenylporphyrin and how does the purification scheme remove most of them in synthesizing tetraphenylporphyrin and cu(TPP) lab.

(a) If the molar solubility of Cd₃(AsO₄)₂ at 25 ^oC is 1.15e-07 mol/L, what is the K_sp at this temperature?

K_sp =  




(b) It is found that 6.47e-05 g of Ag₃AsO₄ dissolves per 100 mL of aqueous solution at 25 ^oC. Calculate the solubility-product constant for Ag₃AsO₄.

K_sp =  




(c) The K_sp of ScF₃ at 25 ^oC is 5.81e-24. What is the molar solubility of ScF₃?

solubility =  mol/L

Reaction 2: 10 mL of 0.1 M CuSO4 and 10 mL of 0.1 M NaOH Calculate the theoretical yield in grams of the product

1)The Ksp of nickel(II) hydroxide, Ni(OH)2, is 5.84 × 10-16. Calculate the solubility of this compound in g/L.

2)The Ksp of CaSO4 is 4.93× 10–5. Calculate the solubility (in g/L) of CaSO4(s) in 0.350 M Na2SO4(aq) at 25 °C.

combustion engine.

Discuss the thermodynamics of the Otto cycle for a combustion engine.

Why does the efficiency depend on the compression ratio?

What is the problem with that? Why is the Otto cycle better than a steam engine? Or, what is the main innovation

Calculate the quantity of energy, in joules, required to raise the temperature of 486 g tin from room temperature, 25.0 °C, to its melting point, 231.9 °C, and then melt the tin at that temperature. (The specific heat capacity of tin is 0.227 , and the enthalpy of fusion of this metal is 59.2 J/g.)

Sketch a graph for a titraton of a weak acid(burette) against 25cm^3 of strong base (conical flask). Assume that both have a concentration of 0.5M. Label axis please!

calculate the amount of energy required to convert saturated water at 150 kpa to superheated steam at 180 C and at the same pressure.

1. You make a solution of 0.464 moles HClO2 and 0.464 moles ClO2- dissolved in 1.00 L. What is the minimum number of moles of KOH would need to be added in order to 'overwhelm' this buffer?

2. You make a solution of 0.316 moles HClO2 and 0.464 moles ClO2- dissolved in 1.00 L. What is the minimum number of moles of KOH would need to be added in order to 'overwhelm' this buffer?

the acid-dissociation constant for benzoic acid is 6.3*10^-5. calculate the equilibrium constant concentration of h30+, C6H5COO-, and C6h5COOH in the solution if the initial concentration of C6H5COOH is 0.050 M

a) Methyl Heptenone contains the elements C, H, and O and has a lemon-like odor. The complete combustion of 192 mg of Methyl Heptenone produces 528 mg of CO₂ and 216 mg of H₂O. What are the percent compositions of C, H, and O in this compound?

b) What is the empirical formula for Methyl Heptenone?

5. Write the chemical structure, synthesis route and biomedical applications of polyethylene glycol?

Calculate the pH at the equivalence point for the following titration: 0.10 M HCOOH versus 0.10 M NaOH. (Formic Acid Ka=1.7 x 10-4)

As a very rough approximation, an electron in a quantum dot can be thought of as an electron in a 3D box. By analogy to the 2D box, write down an expression for the energy levels for an electron in a 3D box (write an expression for the special case of a cubic box, with all sides having a length L)

1. What are the 4 molecular structure of polymers? Write down the relationship between materials's strength and different molecular structure?

2. What are the three phases that a composite has, and what are their roles in the composite?

3. Give 3 examples for the materials that can be used as matrix phase and reinforcement phase.

4. What is the reason of using plies in different directions for some of the laminate composites?