Given the mass of hydrogen = 16.0 oz
Converting 16.0 oz hydrogen to pounds (lb) using the conversion factor 1 lb = 16 oz:

Converting 16.0 lb to g using the conversion factors 1 kg = 2.2 lb, 1 kg = 1000 g:

Heat of combustion of hydrogen = 142 J/g
Calculating the heat released when 16.0 oz is combusted:

It would be 125 centimeters
You can predict it based of the electronegativity