Physical Chemistry Answers

3. (a) Estimate the melting point of ice (M=18.0 g/mol) under a pressure of 10 MPa. Assume that the mass density of ice under these conditions is approximately 0.915 g cm−3 and that of liquid water is 0.998 g cm−3. The entropy of fusion of water is 22.0 J K-1 mol−1at the normal melting point (0.1 Mpa).

(b) When a certain liquid (with M = 46.1 g mol−1) freezes at 1 bar and at −3.65 °C its mass density changes from 0.789 g cm−3 to 0.801 g cm−3. Its enthalpy of fusion is 8.68 kJ mol−1. Estimate the freezing point of the liquid at 100 MPa. (Hint: at equilibrium, △G=△H-T△S=0, △S=△H/T)

4. Dibromoethene (DE, p*DE = 22.9 kPa at 358 K) and dibromopropene (DP, p*DP = 17.1 kPa at 358 K) form a nearly ideal solution. If zDE = 0.60, what is (a) ptotal when the system is all liquid, (b) the composition of the vapor when the system is still almost all liquid?

30g of NaOH was dissolved in 80ml of water.The temperature increased from 27°C to 70°C.Estimate the enthalpy change for the dissolution of NaOH

If the proposed mechanism for the reaction is:

i. I2 → 2 I fast

ii. 2 I → I2 fast

iii. H2 + 2I → 2 HI slow

(a). Identify intermediate for the reaction.

(b). Derive the rate law for the reaction

If the proposed mechanism for the reaction is

i. I2 → 2 I fast

ii. 2 I → I2 fast

iii. H2 + 2I → 2 HI slow

(a). Identify intermediate for the reaction.

(b). Derive the rate law for the reaction

Calculate the ratio of ionized and non-ionized forms of the drug atropine in the stomach (pH = 2.60) and the intestine (pH = 8.60) if its pK = 9.60. Where will the drug be absorbed: in the stomach and/ or intestines?

Calculate the total heat required to raise the temperature of 1 kg of tin from 30C to 300C. 

Tin remain in molten state at 300C. 

Given data for tin is 

Melting point = 231.8C 

Molecular weight = 118.7g 

Latent heat of fusion = 1720 kcal/kg mole 

Heat capacity (Cpm) of solid tin = Cp = 5.05+0.0048T kcal/kg mole K, T is in K. 

Heat capacity of liquid tin between melting point and 300C = 7.64 kcal/kg mole K.

Calculate the apparent volume of distribution (Vd) of a

nebilet (nebivolol) if the single dose (D) with oral

administration was 10 mg, and the initial concentration

(Co) in the serum 50 ug / L. Calculate the clearance of

the nebilet (nebivolol) (C1) if its half-life (t, 2) is 10 hours

The speed of the butadiene dimerization reaction was investigated by measuring the total pressure in a batch reactor operating isothermally at a temperature of 326 degrees Celsius. The measurement results are as follows:

t (minutes) 0 5 10 15 20 25 30 35 40 45 50 55 60 70

Pt (mmHg) 632 611 552 573.5 558.5 545 533.5 523 514 505 497 490 484 473

Calculate the order reaction and the rate constant for the reaction. Then the equation for the rate of reaction

With increase in temperature, transport number of an ion

Increase

Decrease

May increase or decrease

Remain unaffected

Citric acid, a tricarboxylic acid important in intermediary metabolism,

can be symbolized as HA. Its dissociation reactions are H₂A =H* + H₂A™ H₂A = H + HA HAH* + A³ pk = 6.40 If the total concentration of the acid and its anion forms is 0.02M, what are the

pk =3.13 pk = 4.76

individual concentrations of H.A. HA, HA, and Aat pH 5.2?