Diborane is a potential rocket fuel that undergoes combustion according to the reaction,
`B_(2)H_(6)(g) +3O_(2)(g) rarr B_(2)O_(3)(g) +3H_(2)O(g)`
From the following data, calculate the enthalpy change for the combustion of diborane:

Options

A. -2079 kJ / mol
B. -1091 kJ / mol
C. -2045 kJ / mol
D. -762 kJ / mol

Answer

C

Explanation

Required equation `B_(2)H_(6(g))+3O_(2(g)) rarr B_(2)O_(3) +3H_(2)O_((g))` To get required equation,
`({:(B_(2)H_(6(g))rarr2B(s)+3H_(2(g))" "DeltaH_(1) =-46 kJ),(3H_(2)O_((l))rarr 3H_(2)O_((g))" "Delta H_(2)=+132 kJ),(3H_(2(g))+(3)/(2) O_(2(g))rarr3H_(2)O_((l))" "Delta H_(3)=-858 kJ),(2B_((s))+(3)/(2)O_(2(g))rarrB_(2)O_(3(s))" "Delta H_(4)=-1273 kJ):})/({:(B_(2)H_(6(g))+3O_(2(g))rarrB_(2)O_(3)+3H_(2)O_((g))),(Delta H = Delta H_(1) + Delta H_(2)+ Delta H_(3)+Delta H_(4)=-2045" kJ/mol"):})`