Question

Is `Zn(s) + AgNO_3(aq)rarr AgNO_3(s)+Zn(NO_3)_2(aq)` balanced with respect to mass and charge?

Answer 1

Well, you tell us....is `1+2+3=3+2`...? I think not...

Explanation:

You gots...

`underbrace(Zn(s) + AgNO_3(aq))rarr underbrace(AgNO_3(s)+Zn(NO_3)_2(aq))`

`(Zn+Ag+N+3xxO)` `rarr` `(Zn+Ag+3N+9xxO)`

Now while both sides are NEUTRAL...CLEARLY there are not the same number of particles, of ATOMS, on each side. Now it is a fact that ALL chemical reactions CONSERVE mass, and CONSERVE charge....and clearly this is unbalanced.... Agreed?

The balanced equation....

`Zn(s) +2AgNO_3(aq) rarr Zn(NO_3)_2(aq) + 2Ag(s)darr`

Now there is a systematic way of doing this in that we could introduce electrons as virtual particles in a redox equation....

`"Oxidation of zinc: loss of electrons"`

`Zn(s) rarrZn^(2+) +2e^(-)` `(i)`

`"Reduction of silver ions: gain of electrons"`

`AgNO_3(aq) +e^(-)rarrAg(s) +NO_3^(-)` `(ii)`

Now both half equation are balanced with respect to mass and charge, as indeed they must be if we purport to represent reality...
To give the final equation, we add `(i)` and `(ii)` in such a way that the electrons are eliminated....i.e. we take `(i)+2xx(ii):`

`Zn(s) +2AgNO_3(aq) +cancel(2e^(-))rarrunderbrace(Zn^(2+)+2NO_3^(-))_("i.e. zinc nitrate") +cancel(2e^(-))+2Ag(s)`

To give after cancellation...

`Zn(s) +2AgNO_3(aq) rarrZn(NO_3)_2(aq) +2Ag(s)`