Question

In conditii standard (1atm,25°C) 1l substanta gazoasa simpla A cu molecule diatomice, cântărește 1.148g.
a)Determinați substanta A
b) Calculati masa unei molecule de A​

Answer 1

P = 1 atm

T = 273 + 25 = 298 K

V = 1 L

m = 1,148 g

niu  = masa/miu(A)

stim ca PV = niuRT

=> PV = (m/miu)RT <=> PVmiu = mRT

=> miu = mRT/PV = 1,148x0,082x298/1x1

= 28 g/mol

A2 = molecula diatomic => A/2 = 28/2 = 14

=> A = N => N2 = molecula de azot

1 mol N2 ..... 28 g ...... 6,022x10la23 molecule

                     x g ........ 1 molecula

=> x = 4,65x10l-23 g