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The Phosphorous content in a fertilizer can be determined absorptimetrically.
Phosphorus (atomic weight = 31) in a mixed fertilizer sample was suitably treated and the resulting solution absorbed 53.80% radiation of wavelength 830 nm. The radiation travelled a distance of 1 cm through the solution.
A 0.6 ppm Phosphorus containing solution showed a transmittance of 35.12% at the same wavelength.
The hydrolysis of ATP (Adenosine triphosphate) to ADP (Adenosine diphosphate) and P (Phosphate) is an important biochemical reaction, with standard free energy change given below:ATP + H2O -----> ADP + P DG0298.15K = -29.3 KJ/mol
The symbols ATP, ADP & P in the above equation stand for different ionised & unionised forms of these substances. However, we will ignore such complications. The standard state for ATP is defined as the state where the sum of concentrations of all forms of ATP is equal to 1 mol/L and with all activity coefficients equal to unity. The same is true for ADP and P.
PEP + H2O <-----> Py + P D G0298.15K = - 53.6 KJ/mol
ADP + P <-----> ATP + H2O D G0298.15K = + 29.3 KJ/mol
Given initial concentrations of PEP and ADP equal to 0.01 mol/L, calculate the concentrations of ATP produced at 298.13 K.
PEP + ADP <-----> ATP + Py
Calculate the amounts of ATP regenerated starting with the same initial concentrations of PEP and ADP stated in part C. Compare the amounts of ATP obtained in parts C & D. State which of the two reactions is more efficient in regenerating ATP.
A research student of chemistry is studying the decomposition reaction of N2 O5
2N2O5 <-----> 4NO2 + O2
The following data are obtained by her:
Derive the expression for rate law which is consistent with the observed kinetic data? (Assume that the concentrations of the intermediate species are negligible during the reaction.)
When a neutron is absorbed by U238, the resulting U239 undergoes two successive beta decays to yield Pu239. The reactions are
92U239 ® -1 b 0 + 93 Np239
93Np239 ® -1 b 0 + 94 Pu 239
The half life of the first decay is 23 mins and that of second decay is 56 hrs. This reaction is of great importance in the context of breeding the fissile Plutonium from natural Uranium. A sample of natural Uranium is irradiated by neutrons for 15 mins. Make suitable approximations and estimate the ratio of Neptunium to Plutonium atoms after a week.
A sample of fuel oil has C/H ratio 9.33 (by weight) and contains 1.37% sulphur by weight. The net calorific value of the fuel oil is 9478.74 kcal/kg at 25oC. What is the gross calorific value? Latent heat of water is 583.2 kcal/kg.
An effluent sample from a formaldehyde plant is known to contain methanol and formaldehyde. The analysis of the solution indicated that the total organic carbon content (TOC) and theoretical oxygen demand (ThOD) are 258.3 mg/L and 956.3 mg/L respectively. Find the concentration of each of the compounds in the sample.
In 1874, Wilhelm Koerner pointed out that if all the positions on a benzene ring are equivalent, there should exist only three disubstituted benzene namely, ortho, meta and para. These should be distinguished by the numbers of isomers each would yield when an additional substituent is introduced.
A certain organic compound A of unknown origin was analysed as follows:-
I CHEMICAL ANALYSIS DATA
II RELATIVE MOLECULAR MASS DATA
1.85 g of A is produced on evaporating 535.3 cm3 of vapour at 342K and 730mm Hg (97.3 KPa).(Gram molecular volume is 22.4dm3 at STP.)
III PHYSICAL DATA
i) From chemical analysis data, deduce possible structures for A and B
ii) From relative molecular mass data, deduce the molecular mass of A.
iii) From physical data, identify A.
Explain your reasoning in all the cases.
a) Precipitate at low pH.
b)Increase in solubility, then decrease in solubility and finally precipitation as the ionic strength is increased from zero to high value.
c) Precipitate on heating.
d) Decrease in solubility as the dielectric constant of the medium is decreased by addition of a water-miscible non-polar solvent.
e) Denaturation if the dielectric constant is decreased substantially (non-polar solvent).
a) Write solution structures of these amino acids at pH 6.1.
b) Predict the order of elution of the amino acids from the ion-exchange column.
c) Are the amino acids separated from each other? Explain.
d) Suppose you have a weakly acidic ion-exchange column, also at pH 6.1. Predict the order of elution of the amino acids from this column.
e) Propose a strategy to separate the amino acids using one or both columns. Explain your rationale (Assume only ionic interactions).
CoCl2 aq + NH3 aq + NH4Cl [O] ® [Co(NH3)5Cl] Cl2.
In [Co(NH3)5Cl] Cl2 complex one of the coordinated ammonia molecule can be substituted with Cl- by the reaction of HCl & NaCl and can be precipitated as perchlorate salt by addition of sodium perchlorate. The resulting complex A when dissolved in water and gently heated isomerised to species B. The complex A on reaction with Cl- gave only one isomer of complex product Co(NH3)3Cl3, while B on reaction with Cl- yielded a pair of isomers of Co(NH3)3Cl3. Based on the above explain the following:
a) Why aqueous solution of cobalt (II) salts are used as a starting material rather than aqueous solution of cobalt (III) salts for the preparation of cobalt (III) complexes ?
b) Why cobalt (II) undergoes ready oxidation to corresponding cobalt (III) complex ?
c) Why cobalt (III) shows preference to form octahedral rather than tetrahedral complexes?
d) Draw structures of A and B.
e) Draw and name the isomer of the products, Co(NH3)3Cl3 , produced from A.
f) Draw and name the isomers of the products, Co(NH3)3Cl3, formed from B.
g) How can one distinguish isomers of Co(NH3)3Cl3, with the help of 1H nmr spectroscopy ?