(NH4)3PO4 :
N = 14 * 3 = 42
H = 1 * 12 = 12
P = 31 * 1 = 31
O = 16 * 4 = 64
-------------------------
42+12+31+64 = 149 g / mol
Hope this helps!.
Excuse me not giving an explanation; I haven't even learned chemistry before. I usually give explanations for math/english.
I think it would be for flourine: 7
aluminum: 8
can't help with the rest...
sorry!
Get to know first how many moles in the gas:n = pV/RT= (1.013*10^5*750/760) Pa *1.49*10^-3 m^3/(8.314 J/(molK)*298) n = 0.0601 moles.
The combustion energies are 889 kJ/mol (methane) and 2 220 kJ (propane) x = moles methane, y = moles propane
x*889 + y*2220 = 778 x + y = 0.0601----------- x = 0.267784 moles = 0.267784*100/0.0601 = 44.6 % y = 0.243216 moles = 0.243216*100/0.0601 = 55.4 %
