Question

Calculati R.a,R.m,C.p pentru urmatoarele substanțe: oxid de aluminiu, sulfat de sodiu, carbonat de potasiu, azotat de calciu​

Answer 1

Răspuns:

Al2O3

r.at. Al:O=2:3

r.m Al:O=54:48=9:8

MAl2O3=2×27+3×16=102g/mol

102g Al2O3.....54gAl.......48gO

100gAl2O3.......xgAl........ygO

x=100×24/102=calculează

y=100×48/102=calculeaza

Na2SO4

r.at.Na:S:O=2:1:4

r.m. Na:S:O=46:32:64

MNa2SO4=2×23+32+4×16=142g/mol

142gNa2SO4.....46gNa......32gS..........64gO

100gNa2SO4......xgNa..........ygS..........zgO

x=100×46/142=calculeaza

y=100×32/142=calculeaza

z=100×64/142=calculeaza

K2CO3

r. at. K:C:O=2:1:3

r.m K:C:O=39:12:48

MK2CO3=2×39+12+3×16=138g/mol

138gK2CO3...........78gK......12gC........48gO

100gK2CO3..........xgK.........ygC.........zgO

x=100×78/138=calculeaza

y=100×12/138=calculeazaâ

z=100×48/138=calculeaza

Ca(NO3)2

r.at.Ca:N:O=1:2:6

r.m. Ca:N:O=40:28:96

MCa(NO3)2=40+2×14+6×16=164g/mol

164gCa(NO3)2.........40gCa...........28gN..........96gO

100gCa(NO3)2...........xgCa............ygN............zgO

x=100×40/164=calculeaza

y=100×28/164=calculeaza

z=100×96/164=calculeaza

Explicație: