Given information:
- Density of oak: 0.72 g/cc
- Empirical formula of oak: CH2O
- Dimensions of the log: 1×5×25 cm^3

Calculating the mass of the log:
To calculate the mass of the log, we need to find its volume. The volume of the log can be calculated using the formula:

Volume = Length × Width × Height

Substituting the given values, we get:
Volume = 1 cm × 5 cm × 25 cm = 125 cm^3

Next, we can calculate the mass of the log using the density formula:
Mass = Density × Volume

Substituting the given values, we get:
Mass = 0.72 g/cc × 125 cm^3 = 90 g

Stoichiometry of combustion:
The empirical formula of oak is CH2O, which means it contains one carbon atom, two hydrogen atoms, and one oxygen atom.

During the combustion of oak, the carbon in the log reacts with oxygen in the air to produce carbon dioxide (CO2), while the hydrogen in the log reacts with oxygen to produce water (H2O).

The balanced equation for the combustion of CH2O is:
CH2O + O2 -> CO2 + H2O

From the equation, we can see that for every one mole of CH2O burned, one mole of H2O is produced.

Calculating the moles of CH2O:
To calculate the number of moles of CH2O in the log, we need to convert the mass of the log to moles.

The molar mass of CH2O can be calculated as follows:
(1 carbon atom × atomic mass of carbon) + (2 hydrogen atoms × atomic mass of hydrogen) + (1 oxygen atom × atomic mass of oxygen)

Molar mass of CH2O = (1 × 12.01 g/mol) + (2 × 1.01 g/mol) + (1 × 16.00 g/mol) = 30.03 g/mol

Now, we can calculate the number of moles of CH2O in the log using the formula:
Moles = Mass / Molar mass

Substituting the given values, we get:
Moles = 90 g / 30.03 g/mol = 2.997 mol (approximately 3 mol)

Calculating the mass of water produced:
Since the ratio of CH2O to H2O is 1:1, we can conclude that for every 3 moles of CH2O burned, 3 moles of H2O are produced.

The molar mass of water (H2O) is:
(2 hydrogen atoms × atomic mass of hydrogen) + (1 oxygen atom × atomic mass of oxygen)
= (2 × 1.01 g/mol) + (1 × 16.00 g/mol)
= 18.02 g/mol

Therefore, the mass of water produced can be calculated using the formula:
Mass of water = Moles of H2O × Molar mass of H2O

Substituting the values, we get:
Mass of water = 3 mol × 18.02 g/mol =

54 g