a.) The molar absorption coefficient of a substance dissolved in benzene is measured to be 802 L mol-1 cm-1 at 492 nm. Calculate what fraction of the incident light intensity of that wavelength passes through 2.97 mm of a solution of concentration 3.06 mmol/L. b.) The molar absorption coefficient of a solute at 524 nm is 103 dm3 mol-1 cm-1. When light of that wavelength passes through a 4.70 mm cell containing a solution of the solute, 59.4 per cent of the light was absorbed. What is the concentration of the solution?Ans = ______ mmol dm-3

(c) Aqueous solutions of Co2+ salts are pale pink. They contain the complex ion [Co(H₂O)]2+. Addition of concentrated HCl results in a profound colour change to dark blue, due to formation of [CoC14]. The main absorption bands of [Co(H₂O)6]2+ and [CoC14] occur at 19400 cm¹ (~10 M¹ cm') and 14700 cm¹ (~ 1000 M¹ cm¹), respectively. (i) Explain the difference in the transition energies between the two complexes. (ii) Explain why the absorption band of [CoC14]² is much more intense than that of [Co(H2O)%]2+. (d) Calculate the ligand field stabilisation energy of the following complexes: (i) [Mn(H₂O)6]2+ (ii) [Fe(CN)6]³ (iii) [CoC14]²-

In a photochemical experiment it is observed that 5.78×10-5 mol of uranyl oxalate is decomposed at a wavelength of 300 nm emitted by a lamp in one hour. When acetone was irradiated with the same lamp for 10 hours, the amount of acetone decomposed was found to be 2.32× 10-4 mol. What is quantumyield for the acetone decomposition under the same condition?

Given that the maximum molar absorption coefficient of a molecule containing a carbonyl group is 30 dm3 mol−1 cm−1 near 280 nm, calculate the thickness of a sample that will result in (i) half the initial intensity of radiation, (ii) one tenth the initial intensity.

Calculate the linear momentum of photons of wavelength 350nm. At what speed would a H2 molecule need to travel for it to have the same linear momentum? Pphoton =(mv) H₂ (zamu)(1.66 x 10-27 kg/amu) = mH₂kg Kg

A 0.00002415 mol dm-3 solution of a substance had an absorbance of 0.325 in a 0.5 cm path length cell. Calculate the molar absorption coefficient for the substance

A Beer’s law plot is prepared by plotting absorbance vs molar concentration of the absorbing species. What are the units of the slope? What are the units of the y-intercept?

Estimate the lifetime of a state that gives rise to a line of width (i) 200 MHz, (ii) 2.45 cm−1.

Suppose you measure the absorbance of a yellow dye solution in a 1.00 cm cuvette (b=1.00 cm). The absorbance of the solution at 427 nm is 0.84 . If the molar extinction coefficient of yellow dye at 427 nm is 27400 M–1cm–1, what is the concentration of the solution in M?

A Morse oscillator, V(r) = D[1 − e−a(r—ro)]², has D = 164 kJ/mole and w→ ve 1250 cm-1. Compute the energy level (in cm-1) corresponding to the eigenstate shown below. = (Note that the energy units, 11.9627 J/mole = 1 cm-1. It might be helpful to convert the value of D to units of cm-1 before you evaluate the energy level.) www