Question

1 , 2 3 4 5 6 va rog mult dau coroana e urgentttt

Answer 1

1. md=7g NaCl
ms = 350g sol

C=md/ms*100 = 7/350*100 = Calculează !

2. ms = 200g NaOH
C=30℅
m H2O adăugat = 100g

C=md/ms*100=>md=C*ms/100 = 30*200/100 = 60g NaOH

msf = ms+mH2O adăugat = 200+100 = 300

Cf = md/msf*100 = 60/300*100 = Calculează !!!

3. ms = 400g sol.
C = 10℅
m sare adăugat (md) = 40g

C=md/ms*100 => md=10*400/100 = 40g

mdf = 40+40 = 80g
msf = 400+40 = 440g

Cf = mdf/msf*100 = 80/440*100 = Calculează !!!

4. ms1 = 200g
C1 = 10℅
ms2 = 400g
C2=20℅

md1=C1*ms1/100 = 10*200/100 = 20g
md2=C2*ms2/100 = 20*400/100 = 80g

mdf = 20+80 = 100g
msf = 200+400=600g

Cf=mdf/msf*100 = 100/600*100 = Calculează !!!

5. ms1 = 400g
C1 = 15℅

md1= C1*ms1/100 = 15*400/100 = 60g H2SO4

Vs2 = 400mL
C= 2M
MH2SO4 = 98g/mol

C = md2/M*Vs =] md2 = C*M*Vs = 2*98*0,4 = 78,4g H2SO4

md2 > md1

R: b) S2

6. C= md/M*Vs =] md = C*M*Vs = 0,2*95*0,5 = 9,5g MgCl2

MMgCl2 = 95g/mol