Question

potrzebuje na teraz!!

Answer 1

Odpowiedź:

1. 36g 2. 0,05 mol 3. 2,44 mol/dm3

Wyjaśnienie:

1. mr=300g

Cp=12%

Cp=ms/mr *100%

ms=Cp*mr/100%

ms=12%*300g/100%=36g

2.

Cn=0,2mol/dm3

v=250cm3=0,25dm3

Cn=n/v

n=Cn*v=0,2mol/dm3*0,25dm3=0,05 mol

3.

Masa KOH=56g

v1=250cm3=0,25dm3

Cn1=3mol/dm3

Cn2=1,5mol/dm3

v2=150cm3=0,15dm3

n1=Cn1*v1=3mol/dm3*0,25dm3=0,75 mol

n2= 1,5mol/dm3*0,15dm3=0,225mol

nc=n1+n3=0,75mol +0,225 mol =0,975 mol

vc=v1+v2=0,25dm3+0,15dm3=0,4dm3

Cc=nc/vc=0975mol/0,4dm3=2,44mol/dm3