Mixture......................
The formula mass of a molecule is the sum of the atomic weights of the atoms in the empirical formula of the compound. It is also known as Formula Weight.
The atomic weights of
N = 14.01 amu
H = 1.00 amu
P = 30.97 amu
O = 16.0 amu
Now, we will calculate now the formula mass of a given substance
3(14.01) + 12(1.00) + 1(30.97) + 4(16.0) = 42.03 + 12.00 + 30.97 + 64.0 = 149.0 amu
Therefore, the formula mass for (NH4)3PO4 is 149.0 amu
PV = nRT. Where P = pressure, V = volume, n = number of moles, R = universal gas constant and T = temperature. Hope this helps!
N₂O₄ (g) ⇌ 2 NO₂ (g)
Kc = [ NO₂ ]² / [ N₂O₄ ]
4.2 = [ 0.785 ] [ N₂O₄ ]
[ N₂O₄ ] = 4.2 / 0.785
[N₂O₄ ] = 5.350 M
hope this helps!