Question

Calculati concentratia procentuala masica a unei solutii care se obtine prin dizolvarea a 4 mol de HCl in 73 mol de H2O.

Answer 1

M HCl=1+35,5=36,5
M H2O=2*1+16=18

Transformam molii in grame:

m HCl=4*36,5=146 g 
m H2O=73*18=1314

Avem formula:

$c= \frac{md*100}{ms}$

md=m HCl=146 g
ms=m HCl+m H2O=146+1314=1460 g

Inlocuim in formula si avem:

c=146*100/1460=14600/1460=10 %

Asadar concentratia procentuala a solutiei va fi de 10 %.

Answer 2

md = 4·36,5 = 146g    mH2O = 73·18 = 1314g ⇒ ms = 1460g
⇒ c = 146·100/1460 = 10%