(c) The element europium, Eu exists in nature as two isotopes; 151Eu with a mass of 150.9196 a.m.u and153Eu with a mass of 152.9096 a.m.u. If the average atomic mass of europium is 151.96 a.m.u, calculate the percentage relative abundances of the two isotopes.
(c)When an electron jumps from a certain higher energy level E , to its ground state El, green light in the Balmer series is emitted. If the energy Released during thistransition is 4.071 x 10 19 J determine the:
(i)Wavelength of the green light
(ii)Higher energy level, E2 from which the electron jumps to the ground energy level El.
(b) (i)At 1100C and 454 mmHg. 0.1 lg of ethanoic acid vapour occupies 63.7cm3. At 1560C and 458mmHg, 0.081g of ethanoic acid vapour occupies 66.4cm3. Calculate the molar mass of ethanoic acid in the vapour phase at each temperature.
(ii)Give the interpretation of the results in 3(b)(i)above.
(c)Gas A of a certain volume diffuses for 580.8s while the same volume of gas J diffuses for 300s under identical experimental conditions. Calculate the relative molecular mass of J ifthe relative molecular mass gas A is 120.
(b)18g of compound X distribute themselves between water and equal volume of an immiscible solvent Y so that 2g of X are in water. Calculate to the nearest integer, the percentage of X left in water if 1000cm3of water containing lg of X are extracted by one litre of Y.
(c) (i) When 1.00moI/dm3of CH3COOH were heated with 0.18 mol. of C2H50H in a Idm3closed vessel, 0.829mol. CH COOH remained at equilibrium. Calculate the value of K .
(ii) What mass of ethylethanoate should be present in the equilibrium mixture formed under the same experimental conditions as 6(b)(i) above if 0.30 moles of ethanol were heated with 0.20 moles of ethanoic acid in 1.0dm3closed vessel?