Răspuns:
Explicație:
c=mdx100/ms
c=5x100/400%= 1,25% fals
c,m= niu/V=13/2mol/l=6,5mol/l adevarat
o,2=niu/0,5---> niu=0,1mol Ca(OH)2
miu,Ca(OH)2=74g/mol=====> m=niuxmiu= 0,1x74g=7,4g Ca(OH)2 fals
miu,MgO=40g/mol niu,MgO=60/40mol=1,5mol
c,m=niu/V---> V= 1,5/5 L= 0,3L=300ml adevarat
c3=md3x100/ms3 unde md3=md1+md2
ms3= ms1+ms2=300g
md1=c1xms1/100= 45g
md2= c2xms2/100=22,5g
md3=67,5g
c3=67,5x100/300%=22,5%
