1.How do acid-base reactions differ from oxidation-reduction (or "redox") reactions?
Answer
Acid-base reactions involve an exchange of protons whereas redox reactions involve an exchange of electrons.<<<
Acid-base reactions and redox reactions involve different processes and have nothing in common.
2.Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?
Answer
Thick zinc walls prevent the battery from over heating.
The zinc walls are transformed into zinc ions as the battery provides electricity<<<<
3.Why are combustion reactions generally exothermic?
Answer
Hydrogen easily pulls electrons from the oxygen in water molecules and are reduced.
Combustion involves the transfer of electrons to oxygen, which has an extremely high tendency for gaining electrons.<<<?? maybe
To answer the question of how combustion reactions are generally exothermic, we need to understand the concept of exothermic reactions. Exothermic reactions are chemical reactions that release heat energy to the surroundings. In the case of combustion reactions, they involve the reaction of a fuel (such as a hydrocarbon) with oxygen. During combustion, the fuel reacts with oxygen to form carbon dioxide and water vapor.
In the reaction, the carbon and hydrogen atoms in the fuel molecules combine with oxygen atoms to form carbon dioxide and water. This process releases a significant amount of energy in the form of heat. The heat is released because the combustion reaction involves the transfer of electrons from the fuel molecules to oxygen.
Oxygen has a high electronegativity, which means it has a strong tendency to attract electrons. As a result, oxygen molecules have a high affinity for gaining electrons. During combustion, the fuel molecules lose electrons, which are transferred to the oxygen molecules.
This transfer of electrons releases energy due to the difference in electronegativity between the fuel and oxygen. The released energy is in the form of heat, making the combustion reaction exothermic. Essentially, the combustion reaction harnesses the energy stored in the fuel and releases it in the form of heat.
So, to summarize, combustion reactions are generally exothermic because they involve the transfer of electrons to oxygen, which has an extremely high tendency for gaining electrons.