Question

consider the following data for selenium:

atomic mass: ( 78.96 \frac { g } { mathrm { mol } } )
electronegativity: ( 2.55 )
electron affinity: ( 195.0 \frac { mathrm { kj } } { mathrm { mol } } )
ionization energy: ( 941.0 \frac { mathrm { kj } } { mathrm { mol } } )
heat of fusion: ( 5.4 \frac { mathrm { kj } } { mathrm { mol } } )

you may find additional useful data in the aleks data tab.

(1) ( mathrm { se } ( g )
ightarrow mathrm { se } ^ { + } ( g ) + e ^ { - } )
does the following reaction absorb or release energy?
release
absorb
cant be decided with the data given.

is it possible to calculate the amount of energy absorbed or released by reaction (1) using only the data above?
yes
no

if you answered yes to the previous question, enter the amount of energy absorbed or released by reaction (1): ( square mathrm { kj } / mathrm { mol } )

(2) ( mathrm { se } ^ { + } ( g ) + e ^ { - }
ightarrow mathrm { se } ( g ) )
does the following reaction absorb or release energy?
release
absorb
cant be decided with the data given.

is it possible to calculate the amount of energy absorbed or released by reaction (2) using only the data above?
yes
no

if you answered yes to the previous question, enter the amount of energy absorbed or released by reaction (2): ( square mathrm { kj } / mathrm { mol } )

Explanation:

Step1: Analyze reaction (1)

The reaction \(Se(g)\to Se^{+}(g)+e^{-}\) is the ionization of selenium. Ionization energy is the energy required to remove an electron from an atom in the gas phase. Since energy is needed to remove the electron, this reaction absorbs energy. And the ionization energy value for selenium is given as \(941.0\frac{kJ}{mol}\), so it is possible to calculate the energy absorbed.

Step2: Analyze reaction (2)

The reaction \(Se^{+}(g)+e^{-}\to Se(g)\) is the reverse of ionization. The energy change for this reverse process is the negative of the ionization energy. So this reaction releases energy and the amount of energy released is equal to the ionization energy value.

Answer:

• For reaction (1): absorb, yes, \(941.0\)
• For reaction (2): release, yes, \(941.0\)