Chemistry Assignment Example | Topics and Well Written Essays - 250 words

Chemistry - Assignment Example Question 1: En=-(13.6eV*z ²)/n ², because z=4 it can be written as En=-16*13.6eV / n ² ii) the dependence of quatum numbers n upon l is given by the following formula l=n-1 ÃŽ £2(2*l+1)=2* n ² iii) n=2 for beryllium, so l=1 and can not be 3 d) iii) energy emitted by photon: |Einf- E2|= 0+54.4eV=54.4 eV= 54.4*1.6*10^-19 [J]=8,7*10^-18 [J] 8,7*10^-18 [J] now we should express photon’s frequency from it’ energy: E=h*f => f=E/h f= 8,7*10^-18 [J]/6.63*10^-34 [J*s]=1.31*10^16 [1/s] 1.31*10^16 Hz is ultraviolet spectrum iv) the energy of the lowest energy photon which can be absorbed by beryllium ion is: E2-E1=-54.4eV+217.6=163.2 eV v) it could absorb a photon of a lower energy if its electron was on a higher energetic level i) E1=-16*13.6eV / 1=-217.6eV E2=-16*13.6eV / 4= -54.4eV E3=-16*13.6eV / 9 = -3.067eV Eoo=-16*13.6eV/inf = 0 Question 3 - because ΔH>0 (=29kJ) reaction is endothermic; - I2+Cl2 =2ICL (-29kJ) ΔH=2ΔHICL-ΔHCl2-ΔHI2; - equilibrium will not change as the number of molecules in the left part of the equation equals to the number of molecules in the right part of the equation: I2+Cl2 =2ICL 1+ 1=2 - because it’s endothermic reaction the increase of temperature will cause the shift of equilibrium to the right (forming of ICl); - the reaction will pass faster with the following rate lg (k^(T2/T1)) where k is the reaction rate coefficient; - the presence of catalyst will cause the reaction rate to increase, the equilibrium will cause the shift to the right (forming of ICl) as catalyst mainly reduces activation energy.