have high affinity for non-metals

posses low ionisation potential values

MCQ Questions for Class 11 Medical Chemistry The S-Block Elements Quiz 9

The products obtained on heating

$LiNO_3$ will be:

0%
$Li_2O + NO_2 +O_2$
0%
$Li_3N + O_2$
0%
$Li_2O +NO +O_2$
0%
$LiNO_3 +O_2$

Explanation

$LiNO_{3}$ on heating decomposes to give reddish brown coloured

$NO_{2}$ gas.

$4LiNO_{3}\rightarrow 2Li_{2}O+4NO_{2}+O_{2}$ .

So option A is correct.

Select the correct statements :

0%
Solubility of alkali earth metal's oxide decreases down the group
0%
Solubility of alkaline earth metal's sulphide increases down the group
0%
Solubility of alkali metal's hydroxide increases down the group
0%
Solubility of alkali metal's fluorides increases down the group

Be and Al exhibit many properties which are similar. But the two elements differ in:

0%
forming covalent bonds
0%
forming polymeric hydrides
0%
exhibiting maximum covalency in compounds
0%
exhibiting amphoteric nature in their oxides

The softness of group IA metals increases down the group with increasing atomic number.

0%
True
0%
False

In which property listed below hydrogen does not resemble alkali metals?

0%
Nature of oxide
0%
Reducing nature
0%
Tendency to form cation
0%
Presence of one electron in valence shell

As compared to alkali metals, alkaline earth metals;

0%
are more metallic
0%
have higher densities
0%
are stronger reducing agents
0%
have larger atomic radii

When a standard solution of

$NaOH$ is left in air for a few hours?

0%
a precipitate will form
0%
strength will decrease
0%
strength will increase
0%
the concentration of $Na^{+}$ ions will remain constant

Ease with which hydrides are formed from

$Li$ to

$Cs$ :

0%
decreases
0%
increases
0%
remains the same
0%
none of these

In certain matters, lithium differs other alkali metals, the main reason for this is:

0%
small size of lithium atom and $Li^{+}$
0%
extremely high electropositivity of $Li$
0%
greater hardness of $Li$
0%
hydration of $Li^{+}$ ion

Alkali metals are characterised by:

0%
good conductors of heat and electricity
0%
high melting points
0%
low oxidation potentials
0%
high ionisation potentials

Thermal stability of hydrides of first group elements follows the order;

0%
$LiH > NaH > KH > RbH$
0%
$LiH > KH > NaH> RbH$
0%
$LiH > RbH > KH > NaH$
0%
$LiH > KH > RbH > NaH$

Element in the first column of the periodic table are called alkali metals. These metals have:

0%
a single valency electron
0%
one electron less than an inert gas configuration
0%
high melting points
0%
high ionisation potentials

The solubility of

$MClO_{4} (M=Li, Na, K, Rb)$ increases in order of:

0%
$LiClO_{4}< NaClO_{4}< KClO_{4}< RbClO_{4}$
0%
$NaClO_{4}< RbClO_{4}< LiClO_{4}< KClO_{4}$
0%
$RbClO_{4}< KClO_{4}< NaClO_{4}< LiClO_{4}$
0%
$KClO_{4}< LiClO_{4} < NaClO_{4}<RbClO_4$

Explanation

$LiClO_4$ is most soluble than others in the 1st group. This is because solubility depends on hydration energy which is size-dependent. As the size increases from top to bottom in a group, hydration energy decreases and solubility also decreases.

The correct order is

$RbClO_4<KClO_4<NaClO_4< LiClO_4.$

Increasing order of density is:

0%
Li < K < Na < Rb < Cs
0%
Li < Na < K < Rb < Cs
0%
Cs < Rb < K < Na < Li
0%
K < Li < Na < Rb < Cs

The aqueous solutions of lithium salts are poor conductor of electricity rather than other alkali metals because of:

0%
high ionisation energy
0%
high electronegativity
0%
lower ability of $Li^{+}$ ions to polarise water molecules
0%
higher degree of hydration of $Li^{+}$ ions

Which of the following does/do not impart characteristic color to the flame?

0%
$MgSO_4$
0%
$CaCl_2$
0%
$Sr(NO_3)_2$
0%
$BaCl_2$

Which of the property of alkali metals is not listed correctly?

0%
The least electronegative metal: $Cs$
0%
A natural radioactive metal: $fr$
0%
The alkali metal with lowest density $:K$
0%
The most abuntant alkali metal in earth's crust: $Na$

The alkali metals

0%
form slat like hydrides
0%
posses low ionisation potential values
0%
have low density
0%
have high affinity for non-metals

Correct order of polarising power is

0%
$Cs^+ < K^+ < Mg^{2+} < Al^{3+}$
0%
$K^+ < Cs^+ < Mg^{2+} < Al^{3+}$
0%
$Cs^+ < K^+ < Al^{3+} < Mg^{2+}$
0%
$K^+ < Cs^+ < Al^{3+} < Mg^{2+}$

Explanation

According to Fajan's rule polarising power depends on size of cation and charge on cation.More the charge on cation and smaller the size of cation will leads to high polarising power.

so correct order is

$Cs^{+} < K^{+} < Mg^{2+} < Al^{3+}$

The ionic radii of

$Li^{+}, Na^{+}, K^{+}$ are in which of the following order

0%
$K^{+} > Na^{+} > Li^{+}$
0%
$K^{+} > Na^{+} < Li^{+}$
0%
$K^{+} < Na^{+} < Li^{+}$
0%
$Li^{+} > Na^{+} < K^{+}$

Explanation

As we move down the group number of shell increases and hence radii increases.

So correct order is

$K^{+} > Na^{+} > Li^{+}$

Arrange the following in increasing order of their atomic radius

$Na, K, Mg, Rb$

0%
$Mg < K < Na < Rb$
0%
$Mg < Na < K < Rb$
0%
$Mg < Na < Rb < K$
0%
$Na < K < Rb < Mg$

Explanation

Across a period from left to right atomic radius decreases and down the group atomic radius increases.

So correct order is:

$Mg < Na < K < Rb$

Property of the alkali metals that increases with their atomic number is:

0%
Ionic mobility of their ions in water.
0%
Solubility of their sulphates
0%
Solubility of their carbonates
0%
Solubility of their hydroxides

Diagonal relationship is shown by

0%
Elements of first period
0%
Elements of second period
0%
Elements of third period
0%
(b) and (c) both

In which of the following groups all the three members are of the alkaline earth metals family

0%
$Al_, Sr, Ti$
0%
$Li, Na, K$
0%
$Mg, Ba, Ca$
0%
$Rb, Cs, Fr$

Explanation

$Mg, Ba$ and

$Ca$ belongs to alkaline earth metals family.

Lithium shows diagonal relationship with

0%
$Al$
0%
$Mg$
0%
$Pb$
0%
$Hg$

Which of the following alkali metals is smallest in size?

0%
$Rb$
0%
$K$
0%
$Na$
0%
$Li$

Explanation

$Li$ is smallest in size among the alkali metals as it has minimum number of shells.

Cause of diagonal relationship is

0%
Similar electronic configuration of the elements
0%
Similar $e/r$ ratio of the elements
0%
Similar number of valency electrons in the elements
0%
Same atomic weights of the electrons

Explanation

Diagonal resemblance is due to similar charge to size ratio (i.e.

$e/r\ ratio$ ).

Potassium is kept in

0%
Alcohol
0%
Water
0%
Kerosene
0%
Liquid ammonia

Explanation

Alkali metals are highly reactive metals. They react with

Alcohol -

$2C_2H_5OH+2K \rightarrow 2C_2H_5OK+H_2$

Water -

$2K+2H_2O \rightarrow 2KOH+H_2$

Ammonia -

$K+(x+y)NH_3 \rightarrow \underset {Ammoniated \ cation}{[K(NH_3)_x]^+ }+ \underset {Ammoniated \ electron}{[e(NH_3)_y]^-}$

But they do not react with kerosene.

Alkali metals lose electrons in

0%
$s-$ orbitals
0%
$p-$ orbitals
0%
$d-$ orbitals
0%
$f-$ orbitals

Explanation

Alkali metals lose electrons in

$s-$ orbital because their valence electrons are present in

$s-$ orbitals.

Alkali metals in each period have

0%
Smallest size
0%
Lowest ionization potential
0%
Highest ionization potential
0%
Highest electronegativity

Aluminium is diagonally related to ( in periodic table )

0%
$Li$
0%
$C$
0%
$B$
0%
$Be$

Explanation

Aluminium is diagonally related to beryllium (

$Be$ ).

Which of the following statement is correct regarding alkali metals?

0%
Cation is less stable than the atom
0%
Cation is smaller than the atom
0%
Size of cation and atom is the same
0%
Cation is greater in size than the atom

Which of the following show diagonal relationship

0%
$B$ and $Si$
0%
$B$ and $Al$
0%
$B$ and $Ga$
0%
$B$ and $C$

Explanation

$B$ shows diagonal relationship with

$Si$ .

Beryllium differs from rest of the members of its family (Group

$IIA$ ) in many ways. The reason for this is its

0%
Small size and higher electronegativity
0%
Small size and lower electronegativity
0%
Large size and lower ionisation energy
0%
Large size and larger ionic radius

Explanation

Beryllium differs from the rest of the members of its family (Group

$IIA$ ) in many ways. The reason for this is due to its:

(i) small atomic size.

(ii) high electronegativity.

(iii) absence of

$d$ orbitals.

$Li$ shows the diagonal relationship with

0%
$Mg$
0%
$B$
0%
$Al$
0%
$C$

Explanation

Elements of

$2^{nd}$ period often show resemblance to the element of the

$3^{rd}$ period diagonaly placed to it. This type of behaviour is called as digonal relationship.

$Li$ shows the diagonal relationship with

$Mg$ .

Which of the following is a false statement?

0%
Fluorine is more electronegative than chlorine
0%
Nitrogen has greater $IE_1$ than oxygen
0%
Lithium is amphoteric
0%
Chlorine is an oxidising agent

Electronegative beryllium is approximately equal to that of

0%
Aluminium
0%
Boron
0%
Magnesium
0%
Sodium

Explanation

Element -

$Be\ \ \ \ Al$

Electronegative -

$1.5\ \ \ \ 1.5$

Be has a diagonal relationship with Al.

Rare-earth elements are exhibited by

0%
At. no. 58 to 71
0%
At. no.21 to 30
0%
At. no. 39 to 71
0%
At. no. 81 to 91

Which alkali metal is most metallic in character?

0%
$K$
0%
$Cs$
0%
$Na$
0%
$Li$

Explanation

$Cs > Rb > K > Na > Li$ -- Metallic character decreasing order.

Note: Down the group metallic character increases.

With the increase in atomic weights, melting points of the alkali metals

0%
Increase
0%
Decrease
0%
Remain constant
0%
Do not show definite trend

The most electropositive amongst the alkaline earth metal is

0%
Beryllium
0%
Magnesium
0%
Calcium
0%
Barium

Explanation

As we go down group electropositive character increases because

$I.E.$ decreases.

$Ba$ is the most electropositive element in the group.

The alkali metals are low melting. Which of the following alkali metals is expected to melt if the room temperature rises to

$30^o$ ?

0%
Na
0%
K
0%
Rb
0%
Cs

Which of the following elements would lose an electron easily?

0%
Mg
0%
Na
0%
K
0%
Ca

In the following ions:

$Mn^{3+}$ ,

$V^{3+}$ ,

$Cr^{3+}$ ,

$Ti^{3+}$
(Atomic no. :

$Mn = 25$ ,

$V = 23$ ,

$Cr = 24$ ,

$Ti = 22$ )
Which ion has the highest number of unpaired electrons?

0%
$Mn^{3+}$
0%
$V^{3+}$
0%
$Cr^{3+}$
0%
$Ti^{3+}$

Explanation

$Mn^{3+} (3d^{4}4s^{0})$ . It has

$4$ unpaired electrons.

Which of the following is the outermost shell for elements of period 2?

0%
K shell
0%
L shell
0%
M shell
0%
N shell

Which of the following metal has lowest melting point?

0%
$Na$
0%
$K$
0%
$Rb$
0%
$Cs$

The properties of lithium are similar to those of Mg.
This is because

0%
both have nearly the same size
0%
the ratio of their charge to size is nearly the same
0%
both have similar electronic configurations
0%
both are found together in nature.

Explanation

Answer is option (B)

$Lithium$ shows diagonal relationship with

$magnesium$ since they have almost the same polarizing power i.e., charge/size ratio.

Match List-I with List-II and select the correct answer using the codes given below the lists:
(A)

$BaSO_{4} + ZnS$ (1) Explosive
(B)

$NI_{3}$ (2) Oxidiser in rocket propellants
(C)

$N_{2}O_{4}$ (3) Space capsule
(D)

$KO_{2}$ (4) Pigment

0%
$A - 3, B - 1, C - 4, D - 2$
0%
$A - 4, B - 1, C - 2, D - 3$
0%
$A - 3, B - 4, C - 1, D - 2$
0%
$A - 4, B - 3, C - 2, D - 1$

Explanation

$BaSO_4 + ZnS$ this show pigment type of reaction

$NI_3$ show the explosive type of reaction

$N_2O_4$ show oxidiser in rocket propellsnts

$KO_2$ is show in Space capsule

hence B is correct answer

Metal(s) M in the following equation is/are

$M + N_{2} \overset{\Delta}{\rightarrow}$ Metal nitride

0%
$Na$
0%
$Li$
0%
$Cs$
0%
$Mg$

Mg and Li are similar in their properties due to

0%
Same e/m ratio
0%
same electron afinity
0%
same group
0%
same ionic potential

Explanation

$Li$ and

$Mg$ ions have similar polarising power or ionic potential.

Hence, Option "D" is the correct answer.

CBSE Questions for Class 11 Medical Chemistry The S-Block Elements Quiz 9 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry The S-Block Elements Quiz 9 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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