Răspuns: B
-calculez masa de MgCl2 din solutie
c= mdx100/ms---> md= 20x95/100g= 19gMgCl2
-calculez masa de precipitat, stiind miuMgCl2=95g/mol miuAgCl=143,5g/mol
1mol.......................................2mol sau, in grame
2AgNO3 + MgCl2-----> Mg(NO3)2 + 2AgCl↓
95g....................................2x143,5g
19g...................................x
x=m=57,4AgCl
Explicație: