Tag: chemistry

Questions Related to chemistry

Which of the following are the correct precautions while bending a glass tube?

common laboratory equipments common laboratory apparatus and equipments laboratory equipments know about some common gases chemistry

  1. Select the tube of sufficient length to keep your hands safe from heat.

  2. While heating, the glass tube should be rotated in order to ensure uniform heating.

  3. Never bend the glass tubing by force. Doing so can break the tubing.

  4. All of these

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Correct Option: D
Explanation:

We have to take following precautions while cutting a glass tube:

  • Make a single deep scratch at the desired length with one stroke of file.
  • To avoid injury, hold the glass tube with the help of a thick piece of cloth or wear protective gloves.
  • Heat the end using a Bunsen Burner. Do not heat the end for long time. It may seal the end or make it narrow.
  • Select the tube of sufficient length to keep your hands safe from heat.
  • While heating, the glass tube should be rotated in order to ensure uniform heating.
  • Never bend the glass tubing by force. Doing so can break the tubing.

Corks are ideal stoppers because of:

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  1. its impermeability

  2. absence of toxic substances

  3. availability in a variety of standard sizes

  4. all of the above

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Correct Option: D

 Which type of splicing reaction requires a guanine nucleoside or nucleotide cofactor that is not used as a source of energy?

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  1. Group IV

  2. Group I

  3. Group II

  4. Spliceosomal

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Correct Option: B
Explanation:

Group I type of splicing reaction requires a guanine nucleoside or nucleotide cofactor that is not used as a source of energy. Self splicing group 1 intorns share number of different properties with enzymes which increases tthe reaction rate. The intorns excition the reactiion due to the internal guide sequence.

Which of the following are the correct precautions while cutting a glass tube?

common laboratory equipments common laboratory apparatus and equipments laboratory equipments know about some common gases chemistry

  1. Make a single deep scratch at the desired length with one stroke of file.

  2. To avoid injury, hold the glass tube with the help of a thick piece of cloth

  3. Do not heat the end for long time. It may seal the end or make it narrow.

  4. All of these

Show answer
Correct Option: D
Explanation:

We have to take following precautions while cutting a glass tube:

  • Make a single deep scratch at the desired length with one stroke of file.
  • To avoid injury, hold the glass tube with the help of a thick piece of cloth or wear protective gloves.
  • Heat the end using a Bunsen Burner. Do not heat the end for long time. It may seal the end or make it narrow.

What are the uses of glass/rubber tubes in the laboratory?

common laboratory equipments common laboratory apparatus and equipments laboratory equipments know about some common gases chemistry

  1. It helps cold water to flow in and out of the condenser to allow heated water vapourise

  2. For liquid and gases in the experiment, rubber stoppers are used as plugs in the flask

  3. Rubber tubing is always connected to a condenser, helps in distillation

  4. All of these

Show answer
Correct Option: D
Explanation:

Glass tubing is a long, clear tube used as a passage for liquid or gas in experiments. 
Rubber stoppers are used as plugs in flasks or test tubes. 
Rubber tubing is often connected to a condenser, which is a laboratory tool used in the process of distillation. The rubber tubing helps cool water to flow in and out of the condenser and helps the heated water vapor in the condenser return to its liquid state. 

What is the uses of cork in the laboratory?

common laboratory equipments common laboratory apparatus and equipments laboratory equipments know about some common gases chemistry

  1. It is used as a plug so that the volatile substances do not go out of the container

  2. It also serve as a stopper

  3. Very helpful in fractional distillation

  4. both A and B

Show answer
Correct Option: A,B,C
Explanation:

Corks are useful for stopping of volatile substances to go out, stopper, helps in fractional distillations.

Use of pesticides which do not contaminate soil help in control of ________.

chemistry for a pollution free nature properties of soil soil pollution and its effects soil and soil pollution

  1. air pollution

  2. soil pollution

  3. industrial pollution

  4. none of above

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Correct Option: B
Explanation:

Development of such pesticides should be encouraged, which may save crops from pests and rodents but should not contaminate soil with toxic chemicals.
It is a measure to control soil pollution.

Soil pollution is the outcome of _________.

chemistry for a pollution free nature properties of soil soil pollution and its effects soil and soil pollution

  1. deforestation

  2. pesticides and herbicides

  3. industrial waste

  4. all of above

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Correct Option: D
Explanation:

Most industries are dependent on extracting minerals from the Earth.the industrial waste lingers in the soil surface for a long time and makes it unsuitable for use.
Pesticides and herbicides are used in agricultural practices and these chemicals penetrate into soil and damages them.
Cutting of trees leads to soil erosion.

One of the soil pollutants is _______

chemistry for a pollution free nature properties of soil soil pollution and its effects soil and soil pollution

  1. radioactive substances

  2. pesticides

  3. herbicides

  4. all of above

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Correct Option: D
Explanation:

Radioactive substances resulting from explosions of nuclear testing laboratories and industries giving rise to nuclear dust radioactive wastes, penetrate the soil and accumulate giving rise to land/soil pollution.
Pesticides and herbicides are added in soil in agriculture practices to remove unwanted plants. these chemicals penetrate into soil and damages the soil.

Reducing chemical fertilizer and pesticide use controls _______.

chemistry for a pollution free nature properties of soil soil pollution and its effects soil and soil pollution

  1. soil pollution

  2. global warming

  3. both of them

  4. none of above

Show answer
Correct Option: A
Explanation:

Applying bio-fertilizers and manures can reduce chemical fertilizer and pesticide use. Biological methods of pest control can also reduce the use of pesticides and thereby minimize soil pollution.