There are two Group 17 elements that are gases at STP. They are fluorine and chlorine. <span />
(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!.
Answer:
P₄O₆
Explanation:
The molecular formula is a whole number multiple of the empirical formula. that is, if the mole wt is 219.9 gms/mole and the empirical formula weight is 110 gms/mole*, then the whole number multiple is 219.9/110 = 2 => Molecular formula => (P₂O₄)₂ => P₄O₆.