Question

Care este concentratia molara a unei solutii preparate prin dizolvarea a 195g acid acetic in 1,2 kg apa daca densitatea este de 1,1kg/L? Aceasta solutie se fierbe pana pierde 190g de apa si 1% din acid. Care este concentratia procentuala a solutiei finale? Formula acid acetic: CH3-COOH

Answer 1

Răspuns:

c,m= niu/Vs

md1= 195g

ms1= md1+m,apa= 195g+ 1200g= 1395g= 1,395kg

niu=m/miu=195g/60g/mol= 3,25mol acid acetic\

Vs= m,s1xro= (macid+m,apa)xro=1,395kgx1,1kg/l=  1,5345 l

c,m=3,25mol/1,5345 l=2,1mol/l

md=md1-1x195/100g=195g-1,95g=193.05g

ms= ms1-190g apa- 1x195/100g acid= 1395g- 190g-1,95g=  1203g

c=mdx100/ms= 193,05x100/1203=16%

Explicație: