Q1. What happens chemically when quick lime is added to water?
Q2. How will you test for the gas which is liberated when HCL reacts with an active metal?
Q3. What is an oxidation reaction? Is it exothermic or endothermic? Give one example of oxidation Reaction.
Q4. Give an example of photochemical reaction.
Q5. Give an example of a decomposition reaction. Describe any activity to illustrate such a reaction by heating.
Answers
Answer:
When Calcium oxide i.e. quick lime is added to water filled in a bucket, it reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat. When HCl reacts with an active metal,hydrogen gas is liberated.
Explanation:
1. when quicklime is added to water filled in a bucket react chemically to farm slaked lime and produce heat energy. so so water in the bucket becomes hot.
2. hydrogen gas is liberated when an active metal reacts with hydrochloric acid for testing the presence of hydrogen gas, bring bring a burning candle near the mouth of the test tube in which the reaction is taken place. if if the gas burns with a popping sound then it can be conclude that it is hydrogen.
3. oxidation is a loss of electrons during a reaction by a molecule atom or ion.so it will exothermic.
ex. when copper is heated in the presence of air it gets oxidized to form copper oxide or cuo.
4. example is photosynthesis. the photon from the light energy split water and enable ATP production production that drives the entire process.
5. the example of decomposition reaction is breakdown of hydrogen peroxide to water and the oxygen and breakdown of water to hydrogen and oxygen.
activity.
when lead nitrate is heated in the test tube it forms lead oxide and nitrogen dioxide and oxygen white in colour in a test tube. heat heat this test tube over a flame.
conclusion= decomposition of lead nitrate is a thermal decomposition reaction.