zadatak

sandra's picture

Izracunaj koliko atoma H ima u 51g sledecih jedinjenja

a)stipse

b)Be-hidrida

c)neutralne soli

milicaradenkovic's picture

b) BeH2

n(BeH2)=m/Mr=51/11=4.64 mol

n(H)=2*n(BeH2)=2*4.64=9.28 mol

1 mol-----------------------6*10(23)

9.28 mol--------------------x

x=9.28*6*10(23)/1=5.57*10(24) atoma H

a) ako je u pitanju aluminijeva stipsa KAl(SO4)2*12H2O

n(stipse)=m/Mr=51/474=0.1076 mol

n(H)=24*n(stipse)=24*0.1076=2.58 mol

1 mol----------------------6*10(23)

2.58 mol--------------------x

x=2.58*6*10(23)/1=1.548*10(24) atoma H

sandra's picture

hvala :)

sandra's picture

neutralne soli Al,nisam lepo napisala

milicaradenkovic's picture

neutralne soli kod Al nemaju vodonik jer bi onda to bile kisele soli