Question

Proszę o rozwiązanie 6 zadań z chemi za najlepsze rozwiazanie daje naj z góry dziękuje !!!1

Answer 1

zad.1

mr=200g

Cp=15%

ms=?

 

Cp=ms/mr * 100%   /*mr

Cp*mr=ms*100%     /:100%

ms=Cp*mr/100%

 

ms=15%*200g/100%

ms=30g

 

 

 

zad.2

m=71g

M(Na2SO4)=2*23g/mol+32g/mol+4*16g/mol=142g/mol

Vr=500cm³=0,5dm³

n=?

Cm=?

 

n=m/M

n=71g / 142g/mol

n=0,5mol

 

Cm=n/Vr

Cm=0,5mol/0,5dm³

Cm=1mol/dm³

 

 

 

zad.3

Cm=15,9mol/dm³

d=1,63g/cm³

Vr=1dm³=1000cm³

M(H3PO4)=3*1g/mol+31g/mol+4*16g/mol=98g/mol

Cp=?

 

Cm=n/Vr   /*Vr

n=Cm*Vr

n=15,9mol/dm³*1dm³

n=15,9mol

 

n=m/M   /*M

m=n*M

m=15,9mol*98g/mol

m=1558,2g

 

mr=Vr*d

mr=1000cm³*1,63g/cm³

mr=1630g

 

Cp=ms/mr * 100%

Cp=1558,2g/1630g * 100%

Cp=95,6%

 

 

 

zad.4

Vr1=4dm³

Cm1=0,2mol/dm³

n1=?

 

Cm=n/Vr   /*Vr

n=Cm*Vr

 

n1=0,2mol/dm³*4dm³

n1=0,8mol

 

n2=n1=0,8mol

Vr2=8dm³

Cm2=?

 

Cm2=n2/Vr2

Cm2=0,8mol/8dm³

Cm2=0,1mol/dm³

 

 

 

zad.5

mr1=40g

Cp1=30%

ms1=?

 

Cp=ms/mr * 100%   /*mr

Cp*mr=ms*100%     /:100%

ms=Cp*mr/100%

 

ms1=30%*40g/100%

ms1=12g

 

mr2=150g

Cp2=12%

ms2=?

 

Cp=ms/mr * 100%   /*mr

Cp*mr=ms*100%     /:100%

ms=Cp*mr/100%

 

ms2=12%*150g/100%

ms2=18g

 

ms3=ms2+ms1

ms3=18g+12g

ms3=30g

 

mr3=mr2+mr1

mr3=150g+40g

mr3=190g

 

Cp3=ms3/mr3 * 100%

Cp3=30g/190g * 100%

Cp3=15,8%

 

 

 

zad.6

ms=8,88g

mr=8,88g+100g=108,88g

Cp=?

 

Cp=ms/mr * 100%

Cp=8,88g/108,88g * 100%

Cp=8,15%

Answer 2

1)

mr=200g

Cp=15%

ms=?

ms=Cp*mr/100%

ms=15*200/100

ms = 30g subst.

2)

M Na2SO4=142g/mol

142g soli-----1mol

71g soli-------xmoli

x = 0,5mola

 

Z def. stęż. molowego

0,5mola soli-----500cm3 roztworu

xmoli soli--------1000cm3 roztworu

x = 1mol/dm3 

3) 

M H3PO4=98g/mol

Cm=15,9mol/dm3

d=1,63g/cm3 = 1630g/dm3

Cp=?

Cp=Cm*100%*M/d

Cp=15,9*100*98/1630

Cp = 95,6%

4) 

Z def. stęż. molowego 

0,2mole kwasu-----1dm3 roztworu

xmoli kwasu--------4dm3 roztworu

x = 0,8moli kwasu

DOLANO wody do objętości 8dm3, więc:

0,8mola kwasu-----8dm3 roztworu

xmoli kwasu--------1dm3 roztworu

x = 0,1mol/dm3

5) 

40g 30%...........................x - 12

......................x%

150g 12%........................30 - x 

40/150 = x-12/30-x

40(30-x) = 150(x-12)

1200-40x = 150x-1800

3000 = 190x

x = 15,79% 

6) 

Z def. stęż. procent.

8,88g azotanu-----108,88g roztworu (8,88g azotanu + 100g H2O)

xg azotanu---------100g roztworu

x = 8,16g azotanu

x = 8,16%