(b);;;The concentration of a solute X in water was found to be 8.5g/dm3;at room temperature. 100cm3;of this solution was shaken with 50cm;3;of methyl benzene until equilibrium was obtained. The organic layer was separated and found to contain 0.8g of X.
(i);;;;Calculate the distribution coefficient of X between methyl benzene and water.
(ii);;;What further mass of X would be removed from the aqueous layer if it was shaken with a further 50cm3;of methyl benzene?
(iii);;;;;Calculate the mass of X extracted if IOOcm;3;of methyl benzene was used at once instead of using 50cm3;twice. Which is the more efficient extraction process? Give reason for your answer.
(b);;;;;When 5.8g of acetic acid (CH3C02H) was dissolved in 90g of benzene (C6H6) the freezing point depression was found to be 3.80C. Calculate the degree of association of acetic acid in benzene, given that acetic acid dimerizes in benzene and Kf =5.1;0C mol-I kg
(b);;;;;A photon was absorbed by a hydrogen atom in its ground state and the electron was promoted to the fifth orbit. When the excited atom returned to its ground state, visible radiation and other quanta were emitted.
(i);;;;;;;Briefly explain the transitions made by the electron for the excited atom to return to its ground state.
(ii);;;;;Calculate the wavelength of a photon emitted during a transition from the n1
= 5 state to the n2 = 2 state in the hydrogen atom given that AE = 2.18x10-38