A cube of metal weighs 1.45 kg and displaces 542 ml of water when immersed. Calculate the density of the metal.

The solution is as follows:

The problem would only need the information of 5,600 EJ for the known sources of methane. The molar mass of methane is 16 g/mol.

802 kJ/mol(1000 J/ 1 kJ)(1 mol/16 g)(1000 g/1 kg)(x kg) = 5,600 EJ(10¹⁸ J/1 EJ)
Solving for x,
x = 1.18×10¹⁴ kg of natural gas or methane