Răspuns:a) 1 ,5×10^23
b) 6,022×10^24
Explicație:a
1molHC(c.n)..................................22,4litri
x....................................................5,6litri
x=5,6/22,4=0 ,25 moliHCl
1mol .....................6,022×10^23molecule
0,25mol...................a
a=6,022×0,25×10^23= 1,5×10^23molecule
b) A oxigen=16 Moxigen= 2A=2×16=32g/mol
n=m/M unde n -numar moli, M- masa molara, m- masa,
n=3,2/32=0,1moli
1mol O2 ..................6,022×10^23
0,1................................y
y=0,1×6,022×10^23=6,022×10^22molecule
