Determine the enthalpy of formation of `B_(2)H_(6)`(g) in kJ/mol of the following reaction :
`B_(2)H_(6)(g)+3O_(2)(g)rarrB_(2)O_(3)(s)+3H_(2)O(g)`,
Given : `Delta_(r )H^(@)=-1941 " kJ"//"mol", " "DeltaH_(f)^(@)(B_(2)O_(3),s)=-1273" kJ"//"mol,"`
`DeltaH_(f)^(@)(H_(2)O,g)=-241.8 " kJ"//"mol"`

The fat, C_(57)H_(104)O_(6)(s) , is metabolized via the following reaction. Given the enthalpies of formation, calculate the energy (kJ) liberated when 1.0 g of this fat reacts. C_(57)H_(104)O_(6)(s)+80 O_(2)(g)rarr57CO_(2)(g)=-52 H_(2)O(l) Delta_(f)H^(@)(C_(57)H_(104)O_(6),s)=-70870" kJ"//"mol, "Delta_(f)H^(@)(H_(2)O,l)=-285.8 " kJ"//"mol" , Delta_(f)H^(@)(CO_(2),g)=-393.5 " kJ"//"mol"

The fat, C_(57)H_(104)O_(6)(s) , is metabolized via the following reaction. Given the enthalpies of formation, calculate the energy (kJ) liberated when 1.0 g of this fat reacts. C_(57)H_(104)O_(6)(s)+80 O_(2)(g)rarr57CO_(2)(g)+52 H_(2)O(l) Delta_(f)H^(@)(C_(57)H_(104)O_(6),s)=-70870" kJ"//"mol, "Delta_(f)H^(@)(H_(2)O,l)=-285.8 " kJ"//"mol" , Delta_(f)H^(@)(CO_(2),g)=-393.5 " kJ"//"mol"

The standard enthalpy of formation of ammonia gas is Given: N_(2)H_(4) (g) + H_(2) (g) rarr 2NH_(3) (g), Delta H_(r)^(@) = - 40 kJ//mol DeltaH_(f)^(@) [N_(2)H_(4) (g)] = - 120 kJ//mol

Determine enthalpy of formation for H_(2)O_(2)(l) , using the listed enthalpies of reactions: N_(2)H_(4)(l) + 2H_(2)O_(2)(l) rarr N_(2)(g) + 4H_(2)O(l), Delta_(r)H_(1)^(@) =-818 KJ//"mol" N_(2)H_(4)(l)+O_(2)(g) rarr N_(2)(g) + 2H_(2)O(l), Delta_(r)H_(2)^(@)=-622 KJ//"mol" H_(2)(g)+(1)/(2)O_(2)(g) rarr H_(2)O(l), Delta_(r)H_(3)^(@)=-285 KJ//"mol"

For the reaction 3N_(2)O(g)+2NH_(3)(g)to4N_(2)(g)+3H_(2)O(g),DeltaH^(@)=-879.6kJ If DeltaH_(f)^(@)[NH_(3)(g)]=-45.9kJ" "mol^(-1) , DeltaH_(f)^(@)[H_(2)O(g)]=-241.8kJ" "mol^(-1) Then DeltaH_(f)^(@)[N_(2)O(g)] will be:

Determine enthalpy of formation for H_(2)O_(2)(l) , using the listed enthalpies of reaction : N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l) , " "Delta_(r)H_(1)^(@)=-818kJ//mol N_(2)H_(4)(l)+O_(2)(g)toN_(2)(g)+2H_(2)O(l) " "Delta_(r)H_(2)^(@)=-622kJ//mol H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)" "Delta_(r)H_(3)^(@)=-285kJ//mol

Determine enthalpy of formation for H_(2)O_(2)(l) , using the listed enthalpies of reaction : N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l) , " "Delta_(r)H_(1)^(@)=-818kJ//mol N_(2)H_(4)(l)+O_(2)(g)toN_(2)(g)+2H_(2)O(l) " "Delta_(r)H_(2)^(@)=-622kJ//mol H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)" "Delta_(r)H_(3)^(@)=-285kJ//mol

Determine enthalpy of formation for H_(2)O_(2)(l) , using the listed enthalpies of reaction : N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l) , " "Delta_(r)H_(1)^(@)=-818kJ//mol N_(2)H_(4)(l)+O_(2)(g)toN_(2)(g)+2H_(2)O(l) " "Delta_(r)H_(2)^(@)=-622kJ//mol H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)" "Delta_(r)H_(3)^(@)=-285kJ//mol

Diborane [B_(2)H_(6)(g)] is used as a very effective fuel for rockets. Calculate the heat of combustion of diborane for the following reaction: B_(2)H_(6)(g)+3O_(2)(g)toB_(2)O_(3)(g)+3H_(2)O(g) Given: (1) 2B(s)+(3)/(2)O_(2)(g)toB_(2)O_(3) (s),DeltaH^(0)=-1273kJ*mol^(-1) (2) H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l),DeltaH^(0)=-285.8kJ*mol^(-1) . (3) H_(2)O(l)toH_(2)O(g),DeltaH^(0)=+44kJ*mol^(-1) (4) 2B(s)+3H_(2)(g) to B_(2)H_(6)(g),DeltaH^(0)=+36kJ*mol^(-1) .