Calculate the enthalpy of the reaction
4B(s)+3O2(g)→2B2O3(s)
given the following pertinent information:
a.B2O3(s)+3H2O(g)→3O2(g)+B2H6(g), ΔH∘A=+2035 kJ
b. 2B(s)+3H2(g)→B2H6(g), ΔH∘B=+36 kJ
c. H2(g)+12O2(g)→H2O(l), ΔH∘C=−285 kJ
d. H2O(l)→H2O(g), ΔH∘D=+44 kJ

Respuesta :

Answer:

3,956 KJ

Explanation:

Using the formula below, we can obtain the enthalpy of the reaction:

ΔH = ∑H products ± ∑H reactants. --------------------------------(Formula 1)

∑H products = Sum total of all enthalpies at the product side (left side) of the reaction.

∑H reactants = Sum total of all enthalpies at the reactant side (right side) of the reaction.

∑H products can be obtained by checking the standard enthalpy of reaction of [tex]B_{2}O_{3}[/tex]. This can be obtained from the chemical reaction given in (A) above Δ[tex]H^{0}[/tex] (A) = +2035 KJ

∑H reactants can be obtained by checking the standard enthalpy of reaction of Boron and Oxygen.

The enthalpy of formation of [tex]O_{2}[/tex] = 0. This is a law in thermodynamics. The standard enthalpy of formation of an element in its naturally ocurring state is always = 0 KJ

The enthalpy of formation of Boron can be obtained from the reaction given in equation (b) as Δ[tex]H^{0}[/tex] (B) = +36 KJ

Applying the variables to formula (1) above, we have that

ΔH = 2×(2035) - 4×(36) + 3×(0)

ΔH = 4070 - 114

ΔH = 3,956 KJ