Chemical Reactions and Equations

  • Question 1
    CBSEENSC10013957

    What are some of the waste materials that we generate in our homes?

    Solution
    Some of the the waste materials that we generate in our homes are :
    Spoilt food, vegetable peels, plastic, PUC, used tea leaves, milk packets, empty cartons, used cloths, paper waste, empty medicine bottles, broken foot wear, etc.
    Question 2
    CBSEENSC10013958

    How much time does it take for certain commonly used products to biodegrade, when they are scattered around as litter?

    Solution

    The following chart shows the time taken for commonly used materials to biodegrade:

    Item

    Time taken to biodegrade

    Cotton rags

    1-5 months

    Paper

    2-5 months

    Rope

    3-14 months

    Orange peels

    6 months

    Wool socks

    1-5 years

    Plastic coated paper milk cartons

    5 years

    Leather shoes

    25-40 years

    Nylon fabric

    30-40 years

    Tin cans

    50-100 years

    Aluminium cans

    80-100 years

    Glass bottles

    1 million years

    Plastic bottles

    Do not biodegrade at all

     
    Question 3
    CBSEENSC10013959

    The food we eat is digested by various enzymes in our body. Why the same enzyme does not breakdown everything we eat? What significance does this have for degradation of waste material?

    Solution
    Enzymes are specific in their action, specific enzymes are needed for breakdown of a particular substance. For example, pepsin is needed to breakdown proteins while lipase is needed to digest fats. Because enzymes are specific in their action many human made materials like plastics cannot be broken down by bacteria and other saprophytes. These materials will be acted upon by physical processes like heat and pressure but under the conditions found on the earth these materials persist for a long time.
    Question 4
    CBSEENSC10013960

    Mention some substances that are biodegradable?

    Solution
    Spoiled food, used tea leaves, vegetable peels, cotton rags, waste paper were biodegradable materials.

    Sponsor Area

    Mock Test Series

    Sponsor Area

    NCERT Book Store

    NCERT Sample Papers

    Entrance Exams Preparation