Chemical Thermodynamics and Energetic - Enthalpy of Bond Dissociation

Define enthalpy of sublimation.

Calculate C-Cl bond enthalpy from following reaction:

CH₃Cl_(g) + Cl_2(g) → Ch₂Cl_2(g) + HCl_(g) ΔH° = -104KJ

If C-H, Cl-Cl and H-Cl bond enthalpies are 414, 243 and 431 KJ-Mol^-1 respectively.

For the reaction: Cl₂(g) → 2Cl(g), _______.

(A) ΔH is positive, ΔS is positive

(B) ΔH is positive, ΔS is negative

(C) ΔH is negative, ΔS is negative

(D) ΔH is negative, ΔS is positive

Calculate the standard enthalpy of combustion of CH₃COOH(l) from the following data:

`Delta_fH^@(CO_2)=-393.3 kJ mol^-1`

`Delta_fH^@(H_2O)=-285.8 kJ mol^-1`

`Delta_fH^@(CH_3COOH)=-483.2 kJ mol^-1`

Calculate ΔH° for the reaction between ethene and water to form ethyl alcohol from the
following data:

ΔcH° C₂H₅OH_(l) = -1368 kJ
ΔcH° C₂H_4(g) = -1410 kJ
Does the calculated ΔH° represent the enthalpy of formation of liquid ethanol?

Calculate the standard enthalpy of the reaction, 2C(graphite) + 3H_2(g) → C₂H_6(g), ΔH° = ?

From the following ΔH° values

a) `C_2H_6(g) + 7/2 O_2(g) -> 2CO_2(g) + 3H_2 O(l)`.  ΔH° = -1560kJ

b) `H_2(g) + 1/2 O_2 (g) -> H_2O(l)`  ΔH° = -285.8kJ

c) C(graphite) + O₂(g) -> CO₂(g). ΔH° = -393.5kJ

Calculate ∆H° for the following reaction:

2H₃BO_3(aq) → B2O_3(s) + 3H₂O_(l)

a) H₃BO_3(aq) → HBO_2(aq) + H₂O_(l) , ∆`H_1^@` = − 0.02 kJ

b) H₂B₄O_7(s) → 2B₂O_3(s) + H₂O_(l) , ∆`H_2^@` = 17.3 kJ

c)H₂B₄O_7(s) + H₂O_(l) → 4HBO_2(aq), ∆`H_3^@` = − 11.58 kJ

Calculate the work done in the following reaction at 50°C. State whether work is done on the system or by the system.
`"SO"_2("g") + 1/2"O"_(2("g")) rightarrow "SO"_(3("g"))`