Where does oxidation occur in the electrochemical cell?
in the voltmeter
in the salt bridge
on the zinc electrode
on the copper electrode

The oxidation occur on the zinc electrode.

Explanation:

An electrochemical cell is a device in which chemical energy produced during reaction is converted into electrical energy. in these type of cells oxidation occurs at anode and reduction occurs at cathode.

At cathode :(reduction)

At anode: (oxidation)

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o