Question

6 Calculează masa a 6 moli de amestec echimolar de CaO și MgO.

Answer 1

Răspuns:

188g amestec

Explicație:

amestec echimolar = substantele au acelasi numar de moli (sa zicem x)

$notez\ cu\ n\ nr\ de\ moli\\ \\n_{CaO}=n_{MgO} =x\\6\ moli\ de\ amestec = n_{CaO}+n_{MgO} =x+x=2x, deci\ 2x=6,\ x=6:2, \ x=3\\\boxed{n_{CaO}=n_{MgO} =3\ moli}\\\\\bold{calculam\ masele\ substantelor: }\\n=\frac{m}{M} \\m-masa\\M-masa\ molara/moleculara\\n-nr\ moli\\\\m={n}*{M}\\M_{CaO} =56g/mol\ = > m_{CaO}=3*56=168g\\M_{MgO} =40g/mol\ = > m_{MgO}=3*40=120g\\\\\\m_{amestec}=m_{CaO}+m_{MgO}=168+120=188g\ amestec$