A chemical is composed of hydrogen, oxygen and nitrogen. If 20 moles of the chemical is to be made containing twice as much hydrogen as oxygen and three times as much oxygen as nitrogen how many moles of oxygen is required?	Choose the correct choice.
A) 5 moles  B) 6 moles  C) 8moles  D) 2 moles  E) 1.5 moles
Amount of chemical=20 moles   hydrogen=2 oxygen   oxygen=3 nitrogen   hydrogen+oxygen+nitrogen=20   2 oxygen+oxygen+1/3 oxygen=20   10 oxygen=20   oxygen=2   Answer is 2 moles
<result>D</result>
A chemical is composed of hydrogen, oxygen and nitrogen. If 20 moles of the chemical is to be made containing twice as much hydrogen as oxygen and three times as much oxygen as nitrogen how many moles of oxygen is required?