Molar mass of phosphorus (p) : 30.9 g/mol
1 mole P ----------- 30.9 g
x mole -------------- 2.3 g
30.9 * x = 2.3* 1
30.9 x = 2.3
x = 2.3 / 30.9
x = 0.07 moles
N is as electronegative as Cl is. So Cl doesnt react with O, N
55,000 because 878 is bigger than 499. Also 54 is in the place where 10 is in 10,000.