Answer
(d) MgCl₂
Work Step by Step
If we suggest that magnesium chloride is the unknown compound, so the reaction that occur is:
MgCl₂ (aq) + 2AgNO₃ (aq) → 2AgCl (s) + Mg(NO₃)₂ (aq)
from this reaction we include that n(mol) of AgCl = 2n (mol) of MgCl₂
→ n(mol) of AgCl = mass(g)/Mw(g/mol) = 30.1/143.5 = 0.21 mol
→ n(mol) of MgCl₂ = 0.21/2 = 0.105 mol
so mass of MgCl₂ = 0.105×95.2 = 9.996 g ≈ 10.0 g
