Chemistry
Grade-8
Easy
Question
Identify the substance that is a good conductor of electricity from the following.
- Wood charcoal
- Bone charcoal
- Gas carbon
- All of these
Hint:
The elements which are not very dense have loose electrons making them available for conduction.
The correct answer is: All of these
The correct option is d)All of these.
- Wood and bone charcoal are allotropes of carbon and acts as conductors of electricity
- Graphite is denser and "airier" than charcoal, making electrons more available than charcoal, which may not be as dense as graphite.
- It appears as a compact, amorphous, gray solid that deposits on the walls of vessels containing gaseous carbon.
- It is also an excellent conductor of heat and electricity, similar to graphite.
- Uses include battery plates, arc lamps, and coal gas.
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Which product will form on passing sulfur vapor through red hot charcoal?
Which product will form on passing sulfur vapor through red hot charcoal?
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The amorphous allotropy of carbon that contains the least amount of carbon is
The amorphous allotropy of carbon that contains the least amount of carbon is
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Why is the wood charcoal used in the water filters and gas masks?
1. It is a good adsorbent of gases, liquids, and solids.
2. It is a very good reducing agent.
3. It burns at a very low temperature.
4. It is a soft, black, and porous liquid.
Why is the wood charcoal used in the water filters and gas masks?
1. It is a good adsorbent of gases, liquids, and solids.
2. It is a very good reducing agent.
3. It burns at a very low temperature.
4. It is a soft, black, and porous liquid.
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Which of the following compounds is not carbon's amorphous form?
Which of the following compounds is not carbon's amorphous form?
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Which of the following picture does not depict the uses of wood charcoal?
Which of the following picture does not depict the uses of wood charcoal?
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Wood charcoal acts as
Wood charcoal acts as
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The substance which is present in the highest amount in the ivory black is
The substance which is present in the highest amount in the ivory black is
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Which of the following substance contain almost 99% of carbon?
Which of the following substance contain almost 99% of carbon?
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Sugar charcoal can also be prepared by the following.
The correct option is d)By dehydration of cane sugar.
Sugar charcoal is made by destructive distillation of sugar cane sugar. It is also made by dehydrating sugar in the presence of concentrated sulfuric acid. Sulfuric acid is a dehydrating agent, so it absorbs water from the sugar, leaving behind a black carbon residue.
Sugar charcoal can also be prepared by the following.
ChemistryGrade-8
The correct option is d)By dehydration of cane sugar.
Sugar charcoal is made by destructive distillation of sugar cane sugar. It is also made by dehydrating sugar in the presence of concentrated sulfuric acid. Sulfuric acid is a dehydrating agent, so it absorbs water from the sugar, leaving behind a black carbon residue.
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Identify the substance known as Ivory black from the following.
Identify the substance known as Ivory black from the following.
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Which of the following substance/s reacts with steam or oxides of metals?
Which of the following substance/s reacts with steam or oxides of metals?
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Which of the following forms of carbon occur in nature?
Which of the following forms of carbon occur in nature?
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Fuels are those substances which:
Fuels are those substances which:
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State whether the following statements are correct or incorrect.
(i) The amorphous forms of carbon contain 99 % of carbon.
(ii) The process of gradual conversion of vegetable matter into carbon-rich substances is called carbonization.
(iii) Coal tar is used as a smokeless fuel.
State whether the following statements are correct or incorrect.
(i) The amorphous forms of carbon contain 99 % of carbon.
(ii) The process of gradual conversion of vegetable matter into carbon-rich substances is called carbonization.
(iii) Coal tar is used as a smokeless fuel.
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Read the following paragraph carefully.
The huge forest grows around 300 million years ago covering most of the portion of the earth. Due to the extreme pressure of the earth and high temperature, and the absence of air, the vegetation dies and forms X . This X is compressed between sediment layers to form Y. Further compression forms Z and W, eventually anthracites are formed.
Identify the compounds W, X, Y and Z in the above paragraph:
Read the following paragraph carefully.
The huge forest grows around 300 million years ago covering most of the portion of the earth. Due to the extreme pressure of the earth and high temperature, and the absence of air, the vegetation dies and forms X . This X is compressed between sediment layers to form Y. Further compression forms Z and W, eventually anthracites are formed.
Identify the compounds W, X, Y and Z in the above paragraph:
ChemistryGrade-8
