30) Plastics are used in cars, aircrafts and spacecrafts. 31) Special plastic cookware is used in microwave ovens. 32) Why ionic compounds are having higher melting and boiling points? 33) Is phosphorous stored in kerosene/water? Why? 34) What is energy crisis? How it can be prevented? 35) Why should water not be used to put off fire caused by oils? 36) Why coal and petroleum are called fossil fuels? 37) Why CNG and LPG do called clean fuel?
Answers
Explanation:
32) Ionic compounds have high melting and boiling points because there is a strong electrostatic force of attraction between the oppositely charged ions and hence a large amount of energy is required to break the strong bonding force between ions.
33) Phosphorus is stored in water because phosphorus is very reactive non metal. It catches fire if exposed to air. To prevent the contact of phosphorus with atmospheric oxygen,it is stored in water. ... eventhough sodium is highly reactive it doesn't reacts with oxygen when Na++ is preserved in kerosene.
34) Energy crisis refer to the process of shortage of energy on account of ever increasing demand in the global market. One of the major causes for these crises is the needs and demands of the ever growing population for more energy resources. As compared to the demand, the supply of energy is always less.
There are a number of natural and man made causes that are responsible for energy crises over a period of time. To prevent this crises we can take a number of steps:-
• Try and depend more on renewable energy sources.
• Use products that are more energy efficient.
• Make use of lighting control measures.
• Maintain climate change.
• Try and make use of energy audit features
35) Water isn't used to exinguished fire,because in water oxygen is present, 2) And oxygen gas helps to burn. ... In case of oil fires, water is not suitable for extinguishing the fire because diseal is less dense than water and will float in water.
36) Coal, Oil and Gas are called "fossil fuels" because they have been formed from the fossilized remains of prehistoric plants and animals. Fossil fuels are a nonrenewable energy source since they take millions of years to form. ... The plants that turned into fossils stored energy from the sun by photosynthesis
37) C.N.G (compressed natural gas) is a cleaner fuel because it causes less pollution by emitting fewer pollutants like carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen dioxide, particulate matter, unburned hydrocarbons etc.
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