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Chemistry - Assignment Example

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This paper presents several assignments that concern chemistry issues. To be precise, there are answers for different tasks. Thus, it is stated, "Be" has 4 protons and 11-4=7 neutrons, because it’s neutral it has 4 electrons and hydrogen like beryllium ion has 1 electron. …
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Chemistry Assignment
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Download file to see previous pages Question 1:
En=-(13.6eV*z²)/n², because z=4
it can be written as En=-16*13.6eV / n²
ii) the dependence of quatum numbers n upon l is given by the following formula
Σ2(2*l+1)=2* n²
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)
- 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. ...Download file to see next pagesRead More
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