Tag: chemistry

Questions Related to chemistry

hydrogen peroxid  is not produced by the reaction :-

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. $Na _2O _2 + dil.H _2SO _4$

  2. $Mg + H _2O$

  3. $BaO _2 + HCl$

  4. $BaO _2 + H _3PO _4$

Show answer
Correct Option: B
Explanation:

Sodium peroxide $\left( { Na } _{ 2 }{ O } _{ 2 } \right) $, when it reacts with sulphuric acid $\left( { H } _{ 2 }{ SO } _{ 4 } \right) $, it leads to the formation of sodium sulphate $\left( { Na } _{ 2 }{ SO } _{ 4 } \right) $ with hydrogen peroxide $\left( { H } _{ 2 }{ O } _{ 2 } \right) $.

${ Na } _{ 2 }{ O } _{ 2 }+{ H } _{ 2 }{ SO } _{ 4 }\longrightarrow { Na } _{ 2 }{ SO } _{ 4 }+{ H } _{ 2 }{ O } _{ 2 }$
Also, $Mg+{ H } _{ 2 }O\longrightarrow { Mg\left( OH \right)  } _{ 2 }$
${ BaO } _{ 2 }+HCl\longrightarrow Ba{ Cl } _{ 2 }+{ H } _{ 2 }{ O } _{ 2 }$
${ BaO } _{ 2 }+{ H } _{ 3 }{ PO } _{ 4 }\longrightarrow { Ba } _{ 3 }{ \left( { PO } _{ 4 } \right)  } _{ 2 }+{ H } _{ 2 }{ O } _{ 2 }$
Thus, in all of the above reactions, hydrogen peroxide $\left( { H } _{ 2 }{ O } _{ 2 } \right) $ is formed.

Which of the following is not correctly matched with its uses ?

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. Methanol : As a solvent for paints , varnishes etc.

  2. Ethanol : For denaturing spirit, in manufacture of formaldehyde.

  3. Ethers : To provide inert medium for chemical reactions , as anaesthetic.

  4. All are correctly matched.

Show answer
Correct Option: B
Explanation:
Uses of Methanol are:
1. As a fuel. Methanol burns in air to give carbon dioxide and water.
$2CH _3OH + 3O _2 \rightarrow 2CO _2 + 4H _2O$
2. As a useful fuel for stunt and racing cars as it is less inflammable and can be mixed with water.
3. It is also used as a solvent.
4. Manufacturing other chemicals such as formaldehyde.
5. Being a polar liquid at room temperature, it is used as antifreeze and a denaturant for ethanol.
Uses of Ethanol
1. The alcohol that we drink is simply ethanol.
2. It is also used as a fuel. It burns in air to give carbon dioxide and water and can be used in combination with gasoline (petrol).
$CH _3CH _2OH + 3O _2 \rightarrow 2CO _2 + 3H _2O$

3. A mixture of petrol and ethanol is defined as gasohol with 10-20% ethanol.
4. Ethanol is one of the main ingredients in cosmetics and beauty products.
5. It is used as a food additive. Ethanol helps in evenly distributing food color. It also helps in enhancing the flavor of food extracts.
6. Ethanol is an effective agent that can kill microorganisms like bacteria, viruses, and fungi. Many hand sanitizers use this chemical compound.

Uses of Ether:
Ethers are liquid at room temperature and are typically colorless, with a sweet smell. The most common type of ether is diethyl ether, which is extremely flammable and was one of the first anesthetics used in surgery. Due to its anesthetic effects, ether is also used as an illicit drug to induce sedation and euphoria.

Write the balanced equation for the following :-
Bromoethane and an aqueous solution of sodium hydroxide.

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. $C _2H _5Br+NaOH\rightarrow C _2H _6$

  2. $C _2H _5Br+NaOH\rightarrow C _2H _5OH$

  3. $C _2H _5Br+NaOH\rightarrow C _2H _4O$

  4. $C _2H _5Br+NaOH\rightarrow C _2H _2O$

Show answer
Correct Option: B
Explanation:

Reaction:
$C _2H _5Br+NaOH\rightarrow C _2H _5OH$

Balanced chemical equations for the following:
Monochloro ethane is hydrolysed with aqueous KOH :

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. $CH _3CH _2Cl + KOH \rightarrow C _2H _5OH + HCl + K _2O$

  2. $CH _3CH _2Cl + KOH \rightarrow C _2H _3OH + KCl + H _2O$

  3. $CH _3CH _2Cl + KOH \rightarrow C _2H _3Cl + KOH + H _2$

  4. $CH _3CH _2Cl + KOH \rightarrow C _2H _5OH + KCl + H _2O$

Show answer
Correct Option: D
Explanation:

Reaction:
$CH _3CH _2Cl + KOH \rightarrow  C _2H _5OH + KCl + H _2O$

when alkyl halide is hydrolysed by aq. KOH then corresponding alcohol is formed.

Ethyl alcohol is manufactured by the fermentation of :

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. molasses

  2. starch

  3. both A and B

  4. none of the above

Show answer
Correct Option: C
Explanation:

Commercial manufacturing occurs by fermentatiomn of molasses though natural fermentation in yeasts occurs by conversion of starch to ethanol.

Alcoholic beverages contain:

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. Glycerol

  2. Ethyl alcohol

  3. Methyl alcohol

  4. Isopropyl alcohol

Show answer
Correct Option: B
Explanation:

Alcoholic beverages contain ethyl alcohol (ethanol). Alcohol by volume(ABV) is a standard measure of how much alcohol ethyl alcohol is contained in a given volume of an alcoholic beverage.

Which of the following is an application of ethyl alcohol?

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. as an antiseptic

  2. as an antipyretic

  3. as an antiallergic

  4. as a coagulating agent

Show answer
Correct Option: A
Explanation:

Ethanol is used in medical wipes and in most common antibacterial hand sanitizer gels at a concentration of about 62% v/v as an antiseptic. Ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria and fungi, and many viruses, but is ineffective against bacterial spores.

.................. of molasses takes place in the presence of enzymes.

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. Fermentation

  2. Reduction

  3. Polymerization

  4. Oxidation

Show answer
Correct Option: A
Explanation:

Ethanol can be prepared by the fermentation of molasses. This is a biochemical process in which enzymes react to degrade biomass. Reduction, polymerization and oxidation reactions doesn't necessarily need

Which of the following alcohol is used for making acetaldehyde?

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. Ethanol

  2. Methanol

  3. Propanol

  4. None of the above

Show answer
Correct Option: A
Explanation:

Ethanol is used to prepare acetaldehyde.

$CH _{3}CH _{2}OH + [O] \xrightarrow{KMnO _{4}} CH _{3}CHO + H _{2}O$
So. ethanol on oxidation with potassium permanganate forms acetaldehyde as a product.

Ethanol burns to produce carbon dioxide and water and can be used as :

chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

  1. gas

  2. fuel

  3. antioxidant

  4. free radical

Show answer
Correct Option: B
Explanation:

Ethanol burns to produce carbon dioxide and water and can be used as a fuel on its own or in mixtures with petrol (gasoline). "Gasohol" is a petrol/ethanol mixture containing approximately $10\%$-$20\%$ ethanol.