Answer:
(a) The anode electrode which comprises the zinc electrode being placed in a water solution with low oxygen concentration.
(b) Cathodic reaction is:
⇒ 
Anodic reaction is:
⇒
Explanation:
In the given problem, we have an oxygen-concentration cell consisting of two zinc electrodes. One is immersed in a water solution with a low oxygen concentration and the other in a water solution with a high oxygen concentration. The zinc electrodes are connected by an external copper wire.
(a) Which electrode will corrode?
The electrode that will corrode is the anode electrode which comprises the zinc electrode being placed in a water solution with low oxygen concentration.
(b) Write half-cell reactions for the anodic reaction and the cathodic reaction.
Cathodic reaction is:
⇒ 
Anodic reaction is:
⇒
Answer:
The mass of the reactants compared with the mass of the products should be the same if the reactants are in stoichiometric amounts.
Explanation:
In this question, they ask about chemical reactions and the comparison of the mass of reactants and products. Firstly, it is necessary to introduce the mass conservation principle.
Mass conservation principle mentions that in a chemical reaction, the total mass of reactants is equal to the total mass of products (if the reaction is fully developed). It means mass is not created or destroyed, only transforms from reactants to products.
For example, the mass of sodium plus the mass of chlorine that reactswith the sodium equals the mass of the product sodium chloride.Because atoms are only rearranged in a chemical reaction, there mustbe the same number of sodium atoms and chlorine atoms in both thereactants and products.
Finally, we can conclude that The mass of the reactants compared with the mass of the products should be the same if the reactants are in stoichiometric amounts.
Explanation:
Hydrogen does not obey the octet rule. Boron does not always
obey the octet rule and in fact forms Lewis acids such as BF3 which
only has 6 electrons.
1. condensation
2. evaporation
3. precipitation
4. transpiration
5. dew