Physical Chemistry Answers

The formation enthalpy of palmitic acid C16H32O2 is -848.4 kJ/mole. What is the enthalpy of its combustion?

A sol was obtained by mixing of equal volumes of 0.4 M Copper Sulfate and 0.07 M Sodium Carbonate solutions. Write the reaction equation and micelle structure. What is the charge sign of the micelle?

Estimate pH in a 0.1 M solution of L-3-hydroxybutanoic acid (pKa=4.7).

The hydrated salt Na2Co3. xH2o undergoes 63% loss in mass on heating and become anhydrous. The value of x is;

Estimate the osmotic pressure in 0.5 g/l solution of sucrose in water at 25 oC.

Estimate the concentration of CO32- ions, if potential of the electrode MnCO3/ Mn,CO32- relatively to standard hydrogen electrode is -1.285 V. E0MnCO3/Mn,CO32- = - 1.480 V.

Estimate pH in 0.5 M solution of Ammonium sulfate (pKb=4.75).

A reaction is catalyzed by an enzyme with parameters k=75 s-1, KM=24·10-6 M and concentration [E]0= 2.5·10-6 M. The initial concentration of the substrate is [S]0= 8·10-4 M. Estimate initial reaction rate. Find the substrate’s concentration providing 4-fold decreasing of the reaction rate.

Estimate the concentration of Cadmium (II) ions over the sediment CdCO3, KS=1.0·10-12 M2. 10. The stability constant of the complex of {1-Methyl-2-[5-(5-methyl-isoxazole-3-yl-amino)

The stability constant of the complex of {1-Methyl-2-[5-(5-methyl-isoxazole-3-yl-amino)-1,2,4-thiadiazole-3-yl]-1-methyl-ethyl}-(2,2,6,6-tetramethyl-piperidine-4-yl)-amine (X) with Carboxymethyl-β-cyclodextrin (CM-β -CD) is β=292 M-1. Estimate the concentration of free substance X if its initial concentration is 0.01 M and CM-β -CD concentration is 0.4 M.