Classifying Chemical Reactions LABObservations listed below for 7 reactions and QUESTIONSOBSERVATIONSReaction 1:The zinc metal is dull to start...

Balanced Equations:

you did
not state what was added to the Zn so lets assume HCl.

Zn
(s) +2 HCl (aq) -->  ZnCl2 (aq) + H2 (g)  Single
replacement

In the second reaction the MnO2 acts as a
catalyst in the decomposition of hydrogen peroxide.

2 H2O2
(aq) --> 2 H2O (aq) + O2 (g)

Reaction 3
is a synthesis reaction:

2 Cu (s) + O2 (g) --> 2 CuO
(s)

Reaction 4 is a double replacement
reaction.  The general form is:

AB (aq) + CD (aq)
--> AC (aq)  + BD (s)

reaction 5 is a
decomposition or dehydration type reaction:

CuSO4*5HOH (s)
--> CuSO4 (s) + 5 HOH (l)

Reaction 6 is a
synthesis or hydration reaction:

CuSO4 (s) + 5 HOH (l)
-->  CuSO4*5HOH (s)

Reaction 7 is a single
replacement reaction and is also an oxidation-reduction reaction>  The iron is
oxidized and the copper is reduced.

Fe (s) + CuSO4
(aq)--> FeSO4 (aq)+ Cu (s)

Question 2:  the copper
is combining with the oxygen in the
air.

Question 3: the copper ion is being reduced
to the element so the blue color gradually
disappears.

Question 4:  common signs of a chemical
reaction are:  release of heat or a gas; formation of a precipitate; change in
color.