Question

Ex 4 si 5 . dau coroana

Answer 1

-calculez  md NaCl
c/100=md/ms;   2,8/100=md/200---> 5,6g NaCl
- calculez moli NaCl
n=m/M; n=5,6g/(23gNa+35,5gCl)/mol= 0,096 mol NaCl
-deduc moli AgNO3 din ecuatie
AgNO3+NaCl---> AgCl +NaNO3\
1mol       1mol
n=...........0,096mol-------> n= 0,096mol AgNO3 

-Deduc masa pura NaNO3
p/100= mpur/m,impur;    85/100= m,pur/200----> m,pur= 170gNaNO3
-Calculez moli NaNO3
n=m/M;  n=170g/(23gNa+14gN+3x16gO)/mol= 2molNaNO3
-deduc moli si masa HCl, din ecuatie
HCl+  NaNO3---> NaCl + HNO3
 1mol     1mol        1mol     1mol
2mol........2mol.......2mol......2mol
n=2molHcL= 2molNaCl
m=2molx(36,5g/mol)=71gHCl
-deduc masa solutiei
c/100= md/ms;   36,5/100=71/ms------------------> calculeaza ms !!!