Tag: the s-block elements (alkali and alkaline earth metals)

Questions Related to the s-block elements (alkali and alkaline earth metals)

Which  of the following statement is false?

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $Mg^{2+}$ ion forms a complex with $ATP$

  2. $Ca^{2+}$ ions are important in blood clothing.

  3. $Ca^{2+}$ ions are not important in maintaining the regular beating of the hear

  4. $Mg^{2+}$ ions are important in the green parts of plants

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Correct Option: A

Simple proteins bonded with a non-protein prosthetic group (acting as a cofactor) are called:

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. Simple proteins

  2. Conjugated proteins

  3. Proteonic proteins

  4. All the above

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Correct Option: B
Explanation:

Simple proteins bonded with a non-proteinic prosthetic group (acting as cofactor) are called conjugated proteins.
Examples include  Glycoprotein, Lipoprotein, and Phosphoprotein.

Ripening of fruits can be caried out in presence of :

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $Na _2SO _4$

  2. $NaCl$

  3. $CaCl _2$

  4. $CaC _2$

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Correct Option: D

Which is used for fixing atmospheric nitrogen?

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $CaCN _2$ (nitrolim)

  2. $Li _3N$

  3. $Mg _3N _2$

  4. All of these

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Correct Option: A
Explanation:

For fixing atmospheric nitrogen -nitrolim is used and further $CaCN _2+C$ is used as fertilizer.

Which one of the following has magnesium?

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. Vitamin $B _{12}$

  2. Chlorophyll

  3. Haemocyanin

  4. Carbonic anhydrase

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Correct Option: B
Explanation:

$Mg$ is present in chlorophyll which is a green pigment and is used in photosynthesis in green plants.

Hence option B is correct.

Ripening of fruits can be carried out in the presence of :

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $Na _2SO _4 $

  2. $NaCl$

  3. $CaCl _2$

  4. $CaC _2$

Show answer
Correct Option: D
Explanation:

Calcium carbide is also used for ripening fruit artificially in some countries. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is quite similar in reaction to the natural ripening agent ethylene.

Hence option  D is correct.

State True or False.
Magnesium is an essential constituent of chlorophyll, the green colouring matter of plants.

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. True

  2. False

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Correct Option: A

Nitrolim is a mixture of :

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $CaC _2$ and graphite

  2. $CaCN _2$ and graphite

  3. $Ca(CN) _2$ and graphite

  4. $CaCN _2+N _2$

Show answer
Correct Option: B
Explanation:
 $CaC _2 +N _2\longrightarrow CaCN _2 +C$

When nitrogen is passed over calcium carbide at a suitable high temperature, we get a mixture of $CaCN _2 + Graphite (C)$ known as nitrolim which is a nitrogenous fertiliser." 

A holoenzyme contains apoenzyme and ____________ .

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. isoenzyme

  2. cofactor

  3. inhibitor

  4. none of the above

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Correct Option: B
Explanation:

Holoenzyme = Apoenzyme+ Cofactor.

Apoenzyme:-An apoenzyme is an inactive enzyme, activation of the enzyme occurs upon binding of an organic or inorganic cofactor.
Cofactor:-A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme's activity

For a given sample of water containing the following impurities
$Mg{ \left( H{ CO } _{ 3 } \right)  } _{ 2 }=73mg/L;\quad Ca{ \left( H{ CO } _{ 3 } \right)  } _{ 2 }=162mg/L;\quad Ca{ SO } _{ 4 }=136mg/L$
$Mg{ Cl } _{ 2 }=95mg/L;\quad Ca{ Cl } _{ 2 }=111mg/L;\quad NaCl=100mg/L$
Then the total hardness (temporary and permanent) of above water sample is

chemistry the s-block elements (alkali and alkaline earth metals) biological importance of magnesium and calcium biological importance of elements biological importance of s block elements biological importance of sodium and potassium

  1. $300ppm$

  2. $350ppm$

  3. $450ppm$

  4. $500ppm$

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Correct Option: A