Question

w ilu gramach wody nalezy rozpuscic 40 gramow kwasu octowego , aby otrzymac 10-procentowy roztwor tego kwasu?

Answer 1

mw = x

ms = 40g

cp= 10%

mr= mw=ms

 

10%=ms/mw+ms*100%

mr=mw+ms

 

10%=40g/mw+40g*100%

mr=mw+40g

 

cp=ms/mr*100%

mr=mw+ms

 

10%=ms/mw+ms*100%

mr=mw+ms

 

40g/mw+40g

mr=mw+ms

 

10/100=40g/mw+40g*100%

mr=mw+ms

 

1/10=40/mw+40g

mr=mw+ms

 

1*mw+1*40g=10*40

mr=mw+ms

 

mw=400-40

mr=mw+ms

 

mw=360g

mr=360+40

 

mw=360

mr=400