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s- Block Elements

Description: this test contains questions from s- block elements. the questions are designed as per the latest trend on various competitive examinations
Number of Questions: 25
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Tags: s block elements Alkaline Earth Metals Alkali Metals Alkali Metals (Group-1) Error identification
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Which of the following metal of II A group is not counted as an alkaline earth metal?

  1. Sr

  2. Be

  3. Ba

  4. Rd


Correct Option: B
Explanation:

this answer is correct because Berrylium is having typically small size which leads to formation of covalent compounds and its anamolous propertis because of which it is not considered as an alkaline earth metal compound.

Compounds of alkaline earth metals are extensively hydrated than those of alkali metals because of

  1. high bond dissociation enthalpy

  2. high enthalpy of formation

  3. high hydration enthalpy

  4. none of these


Correct Option: C
Explanation:

this option is correct because higher the hydration enthalpy more molecules of water will get attached to the molecule and hence higher will be the formation of hydrated compounds.

Which one of the following does not give flame test?

  1. Ba

  2. Ca

  3. Sr

  4. Mg


Correct Option: D
Explanation:

this answer is correct because in Mg the outermost electons are tightly bonded because of the nuclear force of attraction and cannot be excited to the higher energy level by the energy provided by the flame and hence it does not respond to the flame test.

Which of the following group II A element is used in radiotherapy used in cancer therapy?

  1. Sr

  2. Ca

  3. Mg

  4. Rd


Correct Option: D
Explanation:

this option is correct because radium is having radioactive isotopes and is used in radiotherapy whic in turn is used in cancer therapy.

Which of the following alkaline earth metals does not react with hydrogen to form hydride?

  1. Be

  2. Mg

  3. Ca

  4. Ba


Correct Option: A
Explanation:

this option is correct because Be being small in size does not react directly to form hydride however its hydride can be obtained by the reduction of berrylum chloride with lithium aluminium hydride as per the following reaction:2BeCl2 + LiAlH4  ------------> 2BeH2 + HCl + AlCl3

Halide of which of the following group II-A metal is soluble in organic solvents?

  1. Mg

  2. Sr

  3. Ca

  4. Be


Correct Option: D
Explanation:

this option is correct because halides of Be are covalent in nature because of its small size and hence are soluble in organic solvents like benzene.

Chlorophyll contains which of the following group II-A elements?

  1. Ca

  2. Mg

  3. Ba

  4. Sr


Correct Option: B
Explanation:

this option is correct because magnesium is present in chlorophyll and helps in capturing he energy from the sunlight for making food for plants.

The hydroxide of which of the following metals is amphoteric in nature?

  1. Mg

  2. Ca

  3. Sr

  4. Be


Correct Option: D
Explanation:

With base: Be(OH)2 + 2OH- ---------> [Be(OH)4]2- With acid: Be(OH)2 + 2HCl + 2H2O -----------> [Be(OH)4]Cl2

Which of the following metal hydroxides has the lowest value of Ksp?

  1. Mg(OH)2

  2. Ca(OH)2

  3. Ba(OH)2

  4. Be(OH)2


Correct Option: D
Explanation:

The hydroxide of beryllium is amphoteric in nature and beryllium has covalent nature also, because of which it is least soluble and has lowest value of Ksp.

Complete the following:

In vapour phase BeCl2 tends to form a

  1. chloro bridged dimer

  2. chloro bridged trimer

  3. chloro bridged monomer

  4. none of these


Correct Option: A
Explanation:

this option is correct because BeCl2 invapour phase exist as a chain structure and forms a chloro bridged dimer.

Metal used as a reducing agent in extraction of boron and silicon is

  1. Ca

  2. Be

  3. Mg

  4. Ba


Correct Option: C
Explanation:

this option is correct because Ma comes higher than Boron and silicon in the electrochemical series hence can be used as a reducing agent in the metallurgy of boron and silicon.

Which of the following is not true regarding alkaline earth metal carbonates?

  1. Solubility increases with increase in the atomic number of the metal ion.

  2. Decompose on heating to give CO2 and respective oxide.

  3. Berryllium carbonate is unstable.

  4. Thermal stability increases with increase in cationic size.


Correct Option: A
Explanation:

this option is correct because actually solubility decreases as the atomic number of the metal ion increases and it becomes less stable with increasing atomic number of the metal ion involved.

Which of the following is the correct order of stability of hydroxides of alkaline earth metals?

  1. Mg(OH)2 > Ca(OH)2 > Sr(OH)2 > Ba(OH)2

  2. Ba(OH)2 > Sr(OH)2 > Ca(OH)2 > Mg(OH)2

  3. Ca(OH)2 > Mg(OH)2 > Sr(OH)2 > Ba(OH)2

  4. Ba(OH)2 > Sr(OH)2 > Mg(OH)2 > Ca(OH)2


Correct Option: B
Explanation:

This option is correct.

When cation exchange resin is treated with hard water, the hardness causing ions get exchanged with

  1. H+ ions

  2. Ca2+ ions

  3. SO42- ions

  4. Mg2+ ions


Correct Option: A
Explanation:

this option is correct because when cation exchange resin is first treated with carboxylic acid it becomes capable of donating its hydrogen ions and when comes in contact with the hardness causing cations it exchanges is H+ ions with the hardness producing cation.

Beryllium does not exhibit coordination number greater than 4 because of

  1. non-availability of s orbital

  2. non-availability of p orbital

  3. non-availability of d orbital

  4. none of these


Correct Option: C
Explanation:

this option is correct because in electronic configuration of be is 1s22s2 which is not involving d orbitals hence it cannot extend its coordination number more than four as its it not having a d orbital.

What is the oxidation sate of K in KO2?

  1. +2

  2. -2

  3. +1

  4. -1


Correct Option: C
Explanation:

This option is correct because superoxide species is represented as O2- since compound on a awhole is neutral hence oxidation state of potassium is +1.

Which of the following ions present in human body is/are responsible for the transmission of nerve signals?

  1. K+

  2. Na+

  3. Both K+ and Na+

  4. Neither K+ nor Na+


Correct Option: B
Explanation:

Sodium remains outside the cell fluid and helps in nerve signal transmission.

+2 oxidation state is generaly not observed in alkali metals because of

  1. high first ionisation enthalpy.

  2. low first ionisation enthalpy

  3. low second ionisation enthalpy

  4. high second ionisation enthalpy


Correct Option: D
Explanation:

this option is correct because in alkali metals when one elctron is detached from the outermost shell then it acquires noble gas configuration resuting in large second ionisation enthalpy and hence it does not show +2 oxidation state.

Which of the following cation is abundant within the cell fluid?

  1. K+

  2. Na+

  3. Both K+ and Na+

  4. Neither K+ and Na+


Correct Option: A
Explanation:

this option is correct because K+ ion is having a great biological significance as it remains present within the cell fluid and supports the sodium pump or sodium potassium pump

Match the compounds in column 1 with their uses in column 2.

 
Column 1 Column 2
(A) Na2CO3 (P) Glass
(B) Na2SiO3 (Q) Bleach
(C) NaOH (R) SO2 absorber
(D) NaOCl (S) detergent
  1. A-S, B-P, C-R, D-Q

  2. A-P, B-R, C-S, D-Q

  3. A-Q, B-S, C-P, D-R

  4. A-R, B-Q, C-S, D-P


Correct Option: A
Explanation:

this option is correct because all the options are correctly matched as sodium carbonate is used as a detergent and sodium silicate in glass, sodium hydroxide in absorption of SO2 and sodium oxy chloride in bleaching action.

Solvay process cannot be extnded to manufacture of K2CO3 because of

  1. high heat of formation of K2CO3

  2. high solubility of K2CO3 in solution

  3. low hydration enthalpy of K+ ion

  4. low ionisation enthalpy of K2CO3


Correct Option: B
Explanation:

This option is correct because of the high solubility of K2CO3 in solution it cannot be precipitated out as Na2CO3 and hence solvay process cannot be employed for the formation of K2CO3

Because of which property of sodium it is used as a coolant in nuclear reactors?

  1. High specefic heat and thermal conductivity

  2. Highly reducing nature

  3. Its catalytic nature

  4. High lusture


Correct Option: A
Explanation:

this option is correct because of this factor only it is usedas a collant as in nuclear eactors it has to withstand high temperatures which is supported by its high specefic heat.

Sodium hydroxide is obtained commercially by the electrolysis of sodium chloride in

  1. lastner-kellner cell

  2. muffle furnace

  3. quinhydrone cell

  4. none of these


Correct Option: A
Explanation:

This option is correct because of electrolysis of brine solution is carried out in castner kellner cell for the formation of sodium hydroxide ommercially.

The correct order of mobilities of alkali metal ions in aqueous solution is

  1. Li+ < Na+ < K+ < Rb+ < Cs+

  2. Cs+ < Rb+ < K+ < Na+ < Li+

  3. Cs+ < Rb+ < Na+

  4. Li+ < K+ < Na+ < Rb+ < Cs+


Correct Option: A
Explanation:

With the increase in atomic number, the extent of hydration decreases and hence, the ions become less heavy, which leads to the higher mobility.

Which of the following is not true regarding solvay process for formation of Na2CO3

  1. CaCl2 is obtained as a by product

  2. Ammonia is recivered by treatment of solution containing NH4Cl with Ca(OH)2

  3. Advantage of high solubility of Na2CO3 is taken

  4. None of these


Correct Option: C
Explanation:

This option is correct because the advantage of low solubility is taken and sodium carbonate is precipitated from the solution

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