Cm = 2,5 M
Vs = 200 mL = 0,2 L
stim ca Cm = niu/Vs
=> niu = CmxVs = 2,5x0,2
= 0,5 moli KOH
miu.KOH = 56 g/mol
niu = masa/miu
=> m = niuxmiu = 0,5x56
= 28 g KOH initial
la finalul reactiei a mai ramas 5,6 g
=> m.reactionat = 28 - 5,6
= 22,4 g KOH
md g 22,4 g
H2SO4 + 2KOH = K2SO4 + H2O
98 2x56
=> md = 98x22,4/2x56
= 19,6 g H2SO4 consumat in reactie
md = 19,6 g
ms = 400 g
stim ca c% = mdx100/ms
=> c% = 19,6x100/400
= 4,9% => corecta c.
