please help?

Question

Given the reaction: Zn(s) + 2 HCl(aq) --> ZnCl2(aq) + H2 (g)

Which statement correctly describes what occurs when this reaction takes place in a closed system?

Atoms of Zn(s) lose electrons and are oxidized.
Atoms of Zn(s) gain electrons and are reduced.
There is a net loss of mass.
There is a net gain of mass.

The diagram represents a chemical cell at 298 K. When the switch is closed, electrons flow from

Al(s) to Ni(s)
Ni(s) to Al(s)
Al3+(aq) to Ni2+(aq)
Ni2+(aq) to Al3+(aq)

Given the reaction: Cu(s) + 4HNO3(aq) --> Cu(NO3)2(aq) + 2NO3(g) + 2H2O(l )
As the reaction occurs, what happens to copper?

It undergoes reduction and its oxidation number decreases.
It undergoes reduction and its oxidation number increases.
It undergoes oxidation and its oxidation number decreases.
It undergoes oxidation and its oxidation number increases.

Answer 1

Zinc Question (You should number these):
Atoms of Zn lose e- and are oxidized; there is never any net gain or loss of mass (LOL)

Cu Question:
Undergoes oxidation and its oxidation number increases.

Cell Question (You don't give a diagram):
Al(s) to Ni(s) through the external circuit.
None of the others is true. In particular, Al3+(aq) flows through the solution to Ni(s).