Question

Whenever organic matter is decomposed under oxygen-free (anaerobic) conditions, methane is one of the products. Thus, enormous deposits of natural gas, which is almost entirely methane, exist as a major source of fuel for home and industry. a. It is estimated that known sources of natural gas can produce 5600 EJ of energy (1 EJ = 1018 J). Current total global energy usage is 4.0 x 102 EJ per year. Find the mass (in kg) of known sources of natural gas. (AH, of methane = -802 kJ mol-'). (4 marks) b. For how many years could these sources supply the world's total energy needs? (2 marks) c. What volume (in L) of natural gas is required to heat 1L of water from 20 °C to 100 °C (Density of water = 1.00 g mL-'; density of methane = 0.72 g L-')? (4 marks) d. The fission of 1 mol of uranium (about 11.3 mL) in a nuclear reactor produces 2 x 1013 J of energy. What volume (in L) of natural gas would produce the same amount of energy? (2 marks)

Answer 1

Date Page No. Ans (3) Natural Gas = Methane (CH4) (molar maes = 16 Ginen known source of Natural gas produce = 5600 EJ energy - 5600 x 108 J ( IEJ= 105) =5681020 To find mass of known source of Natural gas? Ginen SHC Enthalpy of combustion) = - 802 kJ/mol. (-ive sign signifies enothermie ran). - Imole of CH4 produce = 802 kJ energy. 2 802 x 103 J ( IKJ= 1035) . Total no. of moles of CH4 = Total Energy produced Energy produced by linde- 568 1020 802 x 103 = 6.98 x 101s moles 3. mass of che gas : no. of moles x 16. = 6-98x10's to gm = 1.ll x 10 17 gm. там а Си - ). 1 х 20 1 4 - (Natural gas Z

Date Pages Ginen Total global usage per year - 4x10" EJ =4x1020 To find How many years These sources suppy " the world's total energy needs. no. of years : Total energy produced by gas t o energy needed for year 1 568 too a 4 x toto no of year energy - 14 years. Can be used