Q1: Define Electrochemistry and also write down its applications.
Q2: Explain oxidation-Reduction in detail.
Q3: Differentiate between oxidation and reduction?
Following reactions occur when you burn Sui gas.
CH4 + 2O2 → CO2 + 2H2O + heat
Identify the element undergoing oxidation.
Identify elements undergo oxidation and reduction in the following reactions:
In the following reaction identify which element is oxidized and which element is reduced:
2Ca + O2 → 2CaO
In the following reactions, identify which element is oxidized and which element is reduced in terms of electron transfer.
Q4: Define oxidation number and write down rules for assigning oxidation states.
One major problem of air pollution is the formation of acid rain. Air pollutants such as SO2 and NO2 combine with oxygen and water vapours in the air to form H2SO4 and HNO3. These acids fall to the ground with the rain, making the rain acidic. Clouds can also absorb the acids and carry them hundreds of kilometers away where the pollutants are released. Determine the oxidation number of N in NO2 and HNO3, S in SO2 and H2SO4.
Determine the oxidation state of:
A device called breathalyzer is used by police to test a person's breath for alcohol. It contains an acidic solution of potassium dichromate K2Cr2O7. It is a strong oxidizing agent. Determine oxidation state of Cr in it.
Boric acid H3BO3 is used in eye wash. What is the oxidation state of B in this acid?
What is the oxidation number of C in carbonate ion, CO32-?
Q5: Derive the formula of ionic compounds from ionic charges and oxidation numbers? Give at least three examples.
Q6: Use roman numerals to indicate oxidation number of an element in a compound?
Q7: Define and identify oxidizing and reducing agents.
Q8: How can you identify oxidizing and reducing agents in a chemical reaction?
Tungsten is used to make filaments for electric bulbs because it has the highest melting point and high electrical resistance. This metal is obtained from tungsten (VI) oxide, WO3 by reducing it with hydrogen gas.
WO3 + 3H2 → W + 3H2O
1. Identify oxidizing and reducing agents in the following reactions:
Q9: Differentiate between oxidizing and reducing agents.
Q12. Elaborate the term corrosion including formation of rust on iron?
Q13. What are the various techniques used to prevent corrosion, including methods such as coating with paints, alloying, applying a thin metallic layer, and cathodic protection? Explain each method in detail.