1. What is a redox reaction?
2. What is corrosion? Explain its advantage and disadvantage.
3. What is rancidity? How can we reduce the problem of rancidity?
4. How is corrosion different from rusting?
5. What is meant by endothermic and exothermic reactions? Give suitable example for each.
6. Define different types of chemical reaction and give examples for each.
7. Why is photosynthesis considered as an endothermic reaction?
8. In electrolysis of water, why is the volume of gas collected over one electrode double that of the other electrodeWhat is a redox reaction?
Answers
Answer:
Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species, most often with one species undergoing oxidation while another species undergoes reduction.
1) Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species, most often with one species undergoing oxidation while another species undergoes reduction
2) It is the gradual destruction of materials (usually a metal) by chemical and/or electrochemical reaction with their environment. Advantages of corrosion: Galvanic corrosion : The principle on which primary batteries work. The main disadvantages of corrosion of metal are: Lose of metal from the surface.
3) The condition produced by aerial oxidation of fats and oils in foods marked by unpleasant smell and taste is called rancidity. Rancidity can be prevented by adding anti -oxidants to foods containing fats and oils. Rancidity can be prevented by packaging fats and oil containing foods in nitrogen gas.
4) The main difference though between corrosion and rust is that corrosion occurs as a result of the chemical influence and it affects a lot of materials whereas rusting is only accelerated by certain chemicals and usually affects iron substances.
5) Exothermic Reaction: A chemical reaction in which heat is given out is known as exothermic reaction. For example. Endothermic Reaction: A chemical reaction in which heat energy is absorbed is known as endothermic reaction.
6) The five basic types of chemical reactions are combination, decomposition, single-replacement, double-replacement, and combustion. Analyzing the reactants and products of a given reaction will allow you to place it into one of these categories. Some reactions will fit into more than one category.
7) Photosynthesis is an endothermic reaction because sunlight is being absorbed during the reaction and the definition suggests that in a reaction if heat is being absorbed it is termed as an endothermic reaction.
8) Water composition is 2atoms of H and 1atom of O . Therefore H is double than O . The two electrodes collect H and O separately . We know that hydrogen composition in water is double than oxygen , so we find volume of gas collected in one electrode is double than volume of gas collected in another electrade .