Science girl313

Q1: If a person breathes at the rate of 15 respirations per minute, and each respiration involves 0.500 dm^3 of air, calculate the total mass of air breathed in one hour at 280K and 1 arm pressure. Average molar mass of air is 28.8g/mol. Q2: A 600cm^3 gas sample contains only methane, CH4, and ethane,H2C_CH2 . Half of the sample was burned in oxygen and found to produce 486.8cm^3 of dry carbon dioxide at 1atm, 300K. The water produced during combustion had been removed. The remainder of the sample was found to require 187.8cm^3 of hydrogen at 1 arm and 300K to convert the ethene to ethane C2H6. A) determine the molar fraction of methane in the orginal sample? B) what is the mass and density of the original gas sample?