Question

un aliaj cu masa de 10g ce contine cupru si aluminiu , a fost tratat cu acid clor hidric .determina partea de masa a fiecarui metal in aliaj , daca se stie ca in urma reactiei s-au degajat 11,2l (c.n.)de gaze

Answer 1

Cu nu reactioneaza cu acidul, deci H2 provine din reactia Al cu acidul
n(niu),H2=11,2l/22,4l/mol= 0,5mol
1mol................................1,5mol
Al + 3HCl-----> AlCl3 +  3/2H2
27g..................................1,5mol
x...........................................0,5
x=m,Al=9g---> m,Cu=1g

in 10g aliaj......................9gAl.......................1gCu
100g......................................x.....................y..................calculeaza !!!!

Answer 2

aliajul=Cu si Al=10g

Cu+HCl=nu reactioneaza
2Al+6HCl=2AlCl₃+3H₂

1mol....................22.4L
x moli...................8 L
x=8*1/22.4=0.357 moli Hidrogen

1mol.............................2g
0.357 moli....................y
y=0.357*2/1=0.714g Hidrogen

z=masa de aluminiu intrata in reactie
z=2*27*0.714/6=6.426 g Aluminiu

⇒Cuprul=3.574 g