The ability to attract an electron for bonding is called (option B) Electronegativity.
Given 3.72 g of P and 21.28g of Cl, converting these to moles: ( 3.72 g P)(mol P/30.97 g P) = 0.12 mol P (21.28 g Cl)(mol Cl/35.45 g Cl) = 0.60 mol Cl P:Cl = 0.12/0.60, therefore P: Cl =1/5 Therefore, PCl5 hope it helps
C=10⁻⁶ mol/L
pH=14-pOH
pOH=-lg[OH⁻]
pH=14+lg10⁻⁶=14-6=8
B. pH = 8
