Tag: chemistry

Questions Related to chemistry

In ethers the numbering of the parent chain is done in a way:

nomenclature of ethers alcohols, phenols and ethers chemistry

  1. that the carbon atom linked to the -O-atom gets the lowest number.

  2. that the carbon atom linked to the -O-atom gets the highest number.

  3. that the carbon atom which comes from parental hydrocarbon linked to the -O-atom gets the lowest number

  4. none of these

Show answer
Correct Option: A
Explanation:

While doing the numbering of longest parent chain in the ether, it is ensured that the carbon atom linked to the $-O-$ atom gets the lowest number, according to IUPAC nomenclature.

Which of the following statement is not correct in the naming of ethers according to IUPAC rules?

nomenclature of ethers alcohols, phenols and ethers chemistry

  1. Ethers are named as alkoxy alkanes

  2. The numbering of the parent chain is done in such a way so that the carbon atom linked to the -O-atom gets the lowest number.

  3. The two alkyl groups attached to the oxygen are put in alphabetical order

  4. In the case of simple ethers, the prefix tri is attached before the name of the alkyl group.

Show answer
Correct Option: D
Explanation:
If both the alkyl groups attached to the $-O-$ atoms are same, then the prefix 'di' is added before the alkyl group. 
Example: $CH _3-O-CH _3$ is named as dimethyl ether.

Which of the following naming is not given correctly?

nomenclature of ethers alcohols, phenols and ethers chemistry

  1. $C _2H _5 - O - C _2H _5$ is Diethyl ether

  2. $C _6H _5 - O - C _6H _5$ is Diphenyl ether

  3. $C _2H _5 - O - C _6H _5$ is Ethyl phenyl ether

  4. $C _2H _5 - O - C _3H _7$ is Diethyl propylether

Show answer
Correct Option: D
Explanation:

$C _2H _5$ is ethyl and $C _3H _7$ is propyl. Therefore, the correct common name, arranged in alphabetical order will be Ethyl Propyl Ether.

IUPAC name of the compound $CH _3-\underset{\displaystyle CH _3}{\underset{|}CH}-OCH _3$ is:

nomenclature of ethers alcohols, phenols and ethers chemistry

  1. 1 - methoxy - 1 - methylethane

  2. 2 - methoxy - 2 - methylethane

  3. 2 - methoxypropane

  4. isopropylmethyl ether.

Show answer
Correct Option: C
Explanation:

Given molecule: $CH _3-\underset{\displaystyle CH _3}{\underset{|}CH}-OCH _3$

It is an ether $ROR'$. In naming ether, smaller alkyl group among R and R' is treated as side group as alkoxy and the other as alkane along with the position of the alkoxy group. Thus in the given molecule, it is methoxy group at second position of propane (alkane)
$\overset { 1 }{ C } H _{ 3 }-\underset { \overset { 3 }{ C } H _{ 3 } }{ \underset { | }{ \overset { 2 }{ C }  }  }H -OCH _{ 3 }$
Thus its name is: 2-methoxypropane.

Find out the statement which is not correct in the naming of cyclic ethers.

nomenclature of ethers alcohols, phenols and ethers chemistry

  1. If a substituent is an alcohol, the alcohol has higher priority

  2. If a substituent is a halide, ether has higher priority

  3. If both an alcohol group and a halide are present, alcohol has higher priority

  4. If a substituent is an alcohol, the ether has higher priority

Show answer
Correct Option: D
Explanation:

In IUPAC naming of cyclic ethers, if a substituent is an alcohol, the alcohol is given the higher priority over the ether.


Hence, the correct option is $D$

________ is a phosphatic fertilizer.

chemistry chemistry in everyday life common salt some useful compounds in everyday life salts and their properties

  1. Super phosphate

  2. Super sulphate

  3. Urea

  4. All of these

Show answer
Correct Option: A
Explanation:

Super phosphate of lime is a mixture of two salts calcium dihydrogen phosphate $Ca\left( { H } _{ 2 }{ PO } _{ 4 } \right) _{ 2 }$ and calcium sulfate dihydrate ${ CaSO } _{ 4 }\cdot { 2H } _{ 2 }O$

A mixture of sand, salt and water can be separated by using which of the following processes?

chemistry chemistry in everyday life common salt some useful compounds in everyday life salts and their properties

  1. Only evaporation

  2. Only sedimentation

  3. Decantation and filtration

  4. Filtration, evaporation and condensation

Show answer
Correct Option: D
Explanation:

First by filtration sand can be separated from the mixture of sand, salt and water. Then by evaporation the water will get evaporated leaving behind the salt. The evaporated vapours can be collected and condensed to get water.

The main use of salt in the diet is to:

chemistry chemistry in everyday life common salt some useful compounds in everyday life salts and their properties

  1. make the taste of food better

  2. produce in small amounts the hydrochloric acid required for the digestion of food

  3. ease the process of cooking

  4. increase the solubility of food particles in water

Show answer
Correct Option: B
Explanation:

Salt plays a primary role in the process of digestion and absorption. Salt plays a role in digestion by helping to break down food. It creates hydrochloric acid which is very important digestive secretion lining the stomach walls. Salt helps the body to digest food.

Gypsum is added to cooled clinker during cement manufacture:

chemistry chemistry in everyday life common salt some useful compounds in everyday life salts and their properties

  1. because gypsum permits formation of fine powder

  2. to delay the initial setting time of cement

  3. to increase the hardening of cement

  4. to increase the strength of set concrete

Show answer
Correct Option: B
Explanation:

Gypsum is a mineral and is hydrated calcium sulfate in chemical form. Gypsum plays a very important role in controlling the rate of hardening of the cement. During the cement manufacturing process, upon the cooling of clinker, a small amount of gypsum is introduced during the final grinding process.

Gypsum is added to control the “setting of cement”. If not added, the cement will set immediately after mixing of water leaving no time for concrete placing.

Gypsum is added to cement because:

chemistry chemistry in everyday life common salt some useful compounds in everyday life salts and their properties

  1. it makes the cement very hard

  2. it increases the pace of setting of cement

  3. it slows down the initial setting of cement when water is added

  4. none of the above

Show answer
Correct Option: C
Explanation:

Gypsum plays an important role in controlling the rate of hardening of the cement. During cement manufacturing process upon cooling of clinker a small amount of gypsum is added during the final grinding process. Gypsum controls the setting of the cement and if not added the cement will set immediately leaving no time for concrete placing.