Use bond energies (Table below) to estimate H (kJ) for the following gas-phase reaction:

(CH3)2CHOH(g) ==> (CH3)2C=O(g) + H2(g)

To estimate H (enthalpy change) for the given gas-phase reaction using bond energies, we need to follow these steps:

1. Write the balanced equation for the reaction:
(CH3)2CHOH(g) → (CH3)2C=O(g) + H2(g)

2. Determine the bonds broken and formed in the reaction. In this case, the following bonds are broken:
- C-C bond in (CH3)2CHOH
- O-H bond in (CH3)2CHOH

And the following bonds are formed:
- C=O bond in (CH3)2C=O
- H-H bond in H2

3. Look up the bond energies for the specific bonds in a bond energy table. Here is a table of average bond energies (in kJ/mol):

C-H: 413 kJ/mol
C-C: 348 kJ/mol
C=O: 799 kJ/mol
O-H: 463 kJ/mol
H-H: 436 kJ/mol

4. Calculate the total energy required to break the bonds by multiplying the number of each bond by its respective bond energy and summing them up. Then calculate the total energy released by forming the bonds:

Energy required to break bonds:
(4 x C-H) + C-C + O-H

Energy released by forming bonds:
C=O + (2 x H-H)

5. Calculate the net energy change by subtracting the energy released from the energy required:

H = (Energy required to break bonds) - (Energy released by forming bonds)

Let's plug in the values from the bond energy table and calculate the estimate for H:

Energy required to break bonds:
(4 x 413 kJ/mol) + 348 kJ/mol + (1 x 463 kJ/mol) = 2931 kJ/mol

Energy released by forming bonds:
799 kJ/mol + (2 x 436 kJ/mol) = 1671 kJ/mol

H = 2931 kJ/mol - 1671 kJ/mol
H ≈ 1260 kJ

Therefore, the estimated enthalpy change (H) for the given reaction is approximately 1260 kJ.