Tag: chemistry

Questions Related to chemistry

Which one of the following is not an application of green chemistry?

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. Replacement of CFCs by ${CO} _{2}$ as lowing agent in the manufacture of polystyrene foam sheets

  2. Reacting methylamine and phsogene to produce metyl isocyanate

  3. Replacement of organotions by sea-nine as anti fouling compound in sea marines

  4. Catalytic dehydrogenation of the diethanol amine withou using cyanide and formaldehyde

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Correct Option: A

Shrinkage of concrete depends upon the: 

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. relative humidity of the atmosphere & passage of time

  2. the moisture in the surrounding

  3. applied stress

  4. raining factor

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Correct Option: A
Explanation:

 Drying shrinkage is defined as the contracting of a hardened concrete mixture due to the loss of capillary water. This shrinkage causes an increase in tensile stress, which may lead to cracking, internal warping, and external deflection before the concrete is subjected to any kind of loading.

Shrinkage depends upon the relative humidity of the atmosphere & passage of time.
Hence, the correct option is A.

Green chemistry is:

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. way of thinking and utilising the existing knowledge and principles of chemistry and other sciences

  2. study of plants for making the environment clean

  3. both A and B

  4. None of the above

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Correct Option: A
Explanation:

Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the designing of products and processes that minimize the use and generation of hazardous substances.

Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, use, and ultimate disposal

$Statement\ I-$ Algal blooms, caused by phosphates, are beneficial to aquatic ecosystems.
BECAUSE
$Statement\ II-$ Algal blooms are associated with rapidly increasing rates of photosynthesis which lead to dissolve oxygen content in the water leading to much higher than normal levels.

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. Statement $I$ is true, Statement $II$ is true

  2. Statement $I$ is true, Statement $II$ is false

  3. Statement $I$ is false, Statement $II$ is true

  4. Statement $I$ is false, Statement $II$ is false

  5. Statement $I$ is true, Statement $II$ is true and is correct explanation of the phenomena described in $I$

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Correct Option: E

_________ are called the elements of the weather.

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. The temperature

  2. Humidity

  3. Wind speed

  4. All of the above

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Correct Option: D
Explanation:

The elements of weather are:

1. Temperature
2. Humidity
3. Wind speed

The monsoon winds that carry a lot of water to India come from the:

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. North east

  2. North west

  3. South east

  4. South west

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Correct Option: D
Explanation:

The winds coming from the southwest blow over the Indian ocean and bring lots of rains.

What does Green Chemistry in terms of environment mean?

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. Greenhouse effect

  2. Reaction related to depletion of ozone layer

  3. Photosynthetic reactions in plants

  4. Reduction in the use and production of hazardous chemicals

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Correct Option: D
Explanation:

Green chemistry is also known as environmentally sustainable chemistry. 


Perhaps, the most widely accepted definition of green chemistry is the one offered by chemists Paul Anastas and John Warner, who defined green chemistry as the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances.

Hence, option D is correct.

The average weather pattern taken over a long time, say _______, is called the climate of the place.

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. $10\ years$

  2. $20\ years$

  3. $25\ years$

  4. $30\ years$

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Correct Option: C
Explanation:

The average weather pattern taken over a long time of about $25 years$ is known as climate of that place.

All changes in the weather are caused by the:

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. Earth

  2. Sun

  3. Moon

  4. none of the above

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Correct Option: B
Explanation:

The energy that the Earth receives from the Sun is the basic cause of our changing weather. Solar heat warms the huge air masses that comprise large and small weather systems.However, at higher altitudes, the atmosphere reacts strongly to changes in solar activity.

Solvents used to dry clean clothes are usually $C 2Cl _4$ .A substitute has been discovered which is environmental friendly is an application of _________.

chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

  1. Green revolution

  2. Green chemistry

  3. Waste management

  4. Revolution resource recovery

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Correct Option: B
Explanation:

Solvents used to clean dry clothes are usually chlorinated compounds such as tetrachloroethylene $C _2Cl _4$ which is a human potential carcinogen which have serious environmental consequence. a substitute has been discovered which is environmental friendly is an application of green chemistry.