Question

E urgent! Dau coroană!Alegeți varianta corectă: Intr-un litru de apa (p=1 g/mL) se dizolva 307,5 g sare amara (MgS0, -7H,O). Concentratia procentuala a solutiei obtinute este:
A)11,47%
B)23,45%
C)14,32%
D)27,32%

Answer 1

Răspuns:

mH2O= 1000g

MMgSO4*7H2O=120+126=246 G/mol

246gcristolohidrat.....120g sare

307,5g..........................x=150g MgSO4 (md)

ms=1000g+307,5=1307,5g

c=150*100/1307,5=11,47%