World energy supplies are often measured in the unit of quadrillion British thermal units (1012 Btu), generally called a "quad." In 2015, world energy consumption is projected to be 5.81 ×1017kJ.

1.The use of the British thermal unit (Btu) is common in much engineering work. (1 Btu = 1054J) A Btu is the amount of heat required to raise the temperature of 1 lb of water by 1 ?F. How many quads of energy does world energy consumption quantity represent?

2.Current annual energy consumption in the United States is 99.4 quads. Assume that all this energy is to be generated by burning CH4(g) in the form of natural gas. If the combustion of the CH4(g) were complete and 100 % efficient, how many moles of CH4(g) would need to be combusted in order to provide the U.S. energy demand?