Question

Oblicz masy cząsteczkowe:

a) Na2CO3

Ca(OH)2

H3PO4

b) oblicz masy molowe:

K2CO3

Mg(NO3)2

Answer 1

a ) Na2CO3 = 106u 
 cA(oh)2 = 74u
H3PO4 -98u
b) K2CO3 138g/mol
    Mg(NO3)2 - 148 g/mol 

Answer 2

a) M Na = 23u

    M C = 12u

    M O = 16 u

    M Na2CO3 = 2*23u + 12u + 3*16u = 46u+12u+48u=106u

   

    M Ca = 40u

    M O = 16u

    M H = 1u

    M Ca(OH)2 = 40u+2*16u+2*1u = 40u+32u+2u=74u

 

    M H = 1u

    M P = 31u

    M O = 16u

    M H3PO4 = 3*1u+31u+4*16u=3u+31u+64u=98u

 

b) M K = 39g/mol

    M C = 12g/mol

    M O = 16gmol

    M K2CO3 = 2*39g/mol+12g/mol+3*16g/mol=78g/mol+12g/mol+48g/mol=138g/mol

 

    M Mg = 24g/mol

    M N = 14g/mol

    M O = 16g/mol

    M Mg(NO3)2 = 24g/mol+2*14g/mol+2*3*16g/mol=24g/mol+28g/mol+96g/mol=148g/mol