A voltaic cell is assembled by using two 30-mL beakers. In one beaker, Ag metal is used as the electrode with 10 mL of 1 M AgNO3. In the other beaker, Zn metal is used as the electrode with 10 mL of 1 M ZnSO4. The beakers are connected with a salt bridge and the measured cell potential, Eocell, is 1.50 V. The Zn electrode is negative (anode). Which reaction takes place at the Zn electrode

Reaction that takes place at the Zn electrode is oxidation:

Zn ⇄  Zn²⁺  +  2e⁻

Explanation:

This excersise explains the structure of a typical battery, that is useful to study electrochemistry.

AgNO₃ → Ag⁺ + NO₃

ZnSO₄ → Zn²⁺  +  SO₄⁻²

Generally batteries contains 2 electrodes, where we have 2 conductive metallic. Batteries work to obtain electricity from a chemistry reaction which is always a redox type. One electrode releases electrons while the other catch them. Electrons travel from the anode to cathode, so in the anode, the e⁻ are released.

Reaction that takes place at the Zn electrode is oxidation:

Zn ⇄  Zn²⁺  +  2e⁻

Oxidation state is increased, electrons are free to go to cathode, where the other element decreases the oxidation state:

Ag⁺ + e⁻  ⇄ Ag

In the middle of the battery, the salt bridge (generally KCl) contributes the redox with more charges. Cl⁻ for the anode and K⁺ for the cathode.

Note that the same amount of electrons travel from anode to cathode, because in this example, Ag gained 1 mol and Zn released 2 moles.

The scheme for the battery is:

⁻  Zn(s) / Zn²⁺ (aq) //  Ag⁺ (aq) / Ag (s) ⁺

         1 M                               1 M                      

Where the first place represents the anode, // represents the salt bridge and then, the cathode.  Below, we write the molar concentration of each salt.

C. to protect themselves

D.

Explanation:When an animal closely resembles the color of its surroundings, it is known as protective coloring. The color of the animal helps the animal blend in with the environment and makes it harder for predators to see it. This protects the animal from predators.