MCQ Questions for Class 11 Medical Chemistry The S-Block Elements Quiz 7

Which mineral is neccessary for blood clotting?

0%
Calcium
0%
Magnese
0%
Phosphorus
0%
Iron

Explanation

Calcium plays an important role in the coagulation of blood (blood clotting). An increased concentration of calcium in the platelets helps in activating various proteins important for blood clotting and thus, results in the formation of a blood clot. It helps in the binding of clotting enzymes to phospholipids in platelets and tissue and accelerates the reaction.

So, the correct answer is option

$A$ .

The activity of alkaline earth metals as reducing agent :

0%
decreases from $Be$ to $Ba$
0%
increases from $Be$ to $Ba$
0%
increases from $Be$ to $Ca$ and decreases from $Ca$ to $Ba$
0%
decreases from $Be$ to $Ca$ and increases from $Ca$ to $Ba$

Explanation

The activity of alkaline earth metals as reducing agent increases from

$Be$ to

$Ba$ as it can easily lose the valence shell electrons.

Which one of the following alkali metals gives hydrated salts?

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

Explanation

Among alkali metal ions,

${Li}^{+}$ is the smallest which has the highest charge density. Therefore, it has the maximum degree of hydration than any other alkali metal cation.

Which sequence of reactions shows correct chemical relation between sodium and its compounds?

0%
$Na+O_{2}\longrightarrow Na_{2}O\xrightarrow {HCl(aq)}NaCl\xrightarrow {\quad co_{2}\quad}Na_{2}CO_{3}\xrightarrow {\quad \Delta \quad}Na$
0%
$Na\xrightarrow {\quad o_{2}\quad}Na_{2}O\xrightarrow {\quad H_{2}O\quad}NaOH\xrightarrow{\quad co_{2}\quad}Na_{2}CO_{3}\xrightarrow {\quad \Delta \quad}Na$
0%
$Na+H_{2}O\longrightarrow NaOH\xrightarrow {\quad HCl\quad }NaCl\xrightarrow {\quad co_{2}\quad}Na_{2}CO_{3}\xrightarrow {\quad \Delta\quad }Na$
0%
$Na+H_{2}O\longrightarrow NaOH\xrightarrow {\quad co_{2}\quad}Na_{2}CO_{3}\xrightarrow {\quad HCl\quad } \underset{(molten)}{NaCl}\xrightarrow{Electrolysis}Na$

Explanation

$2Na+2H_{2}O\rightarrow 2NaOH+H_{2}$

$2NaOH+CO_{2}\rightarrow Na_{2}CO_{3}+H_{2}O$

$2Na_{2}CO_{3}+2HCl\rightarrow 2NaCl+H_{2}O+CO_{2}$

$\begin{matrix} \underset { (molten) }{ NaCl } & \xrightarrow [ ]{ Electrolysis } & Na^ +&+&Cl^- \\ & &\quad \downarrow +e& &\quad \downarrow-e \\ & & Na&&Cl \end{matrix}$

Which of the following alkali metal ions has lowest ionic mobility in aqueous solution?

0%
$Rb^+$
0%
$Ca^+$
0%
$Na^+$
0%
$Li^+$

Thermal stability of

$BaCO_3, CaCO_3$ and

$MgCO_3$ is:

0%
$BaCO_3 > CaCO_3 > MgCO_3$
0%
$BaCO_3 > MgCO_3 > CaCO_3$
0%
$CaCO_3 > MgCO_3 > BaCO_3$
0%
$MgCO_3 > CaCO_3 > BaCO_3$

Explanation

(i) More be the ionic nature, more be the attractive force between the species.
(ii) More be the attractive force, more be the thermal stability.
(iii) Ionic character for the same anionic species, increases down the group.
Thus, correct order of the thermal-stability is

$BaCO_3 > CaCO_3 > MgCO_3$ .

The element that does NOT form acidic oxide is :

0%
carbon
0%
phosphorus
0%
chlorine
0%
barium

Explanation

The element that does NOT form acidic oxide is

$\displaystyle Barium$ .

$\displaystyle Barium$ is an alkaline earth metal. It forms basic oxide

$\displaystyle BaO$ .

$\displaystyle Carbon$ forms

$\displaystyle CO_2$ which is acidic oxide.

$\displaystyle Phosphorus$ forms

$\displaystyle P_2O_3$ and

$\displaystyle P_2O_5$ which are acidic oxides.

$\displaystyle Chlorine$ forms

$\displaystyle Cl_2O_7$ and other oxides which are acidic oxides.

For the alkali metals, which of the following increases atomic number ?

0%
First ionization energy
0%
Electronegativity
0%
Hydration energy of the univalent ion
0%
Atomic radius

A holoenzyme contains apoenzyme and ____________ .

0%
isoenzyme
0%
cofactor
0%
inhibitor
0%
none of the above

${Li}_{2}{SO}_{4}$ is not isomorphous with sodium sulphate, due to:

0%
small size of lithium
0%
high coordination number of lithium
0%
high ionization energy of lithium
0%
none of the above

Explanation

Isomorphic compounds have same crystal structure at given temperature and conditions. While

$LiSO_4$ and

$Na_2SO_4$ are not isomorphous due to the exceptionally small size of Lithium (Li).

The alkaline earth metal with the least density value is:

0%
$Mg$
0%
$Be$
0%
$Sr$
0%
$Ca$
0%
$Ba$

Explanation

The density of elements of

$IIA$ group first decreases from

$Be$ to

$Ca$ and then steadily increases from

$Ca$ to

$Ba$ . Thus,

$Ca$ has the least density.

Among the following the least thermally stable is:

0%
$K_{2}CO_{3}$
0%
$Na_{2}CO_{3}$
0%
$BaCO_{3}$
0%
$Li_{2}CO_{3}$

Explanation

Thermal stability of carbonates increases on moving down a group. Thus, lithium carbonate,

$Li_{2}CO_{3}$ is least thermally stable.

$Li_{2}CO_{3}\xrightarrow {\triangle} Li_{2}O + CO_{2}\uparrow$ .

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

0%
$SrSO_4$
0%
$CaSO_4$
0%
$BeSO_4$
0%
$BaSO_4$

Explanation

Hydration energy decreases down the group, whereas lattice energy remains almost constant.

Thus, hydration enthalpy is higher than the lattice enthalpy in case of

$BeSO_4$ as the charge density in

$Be^{2+}$ is high.

Hence,option

$C$ is correct.

The set representing the correct order of ionic radii is:

0%
${ Li }^{ + }>{ Be }^{ 2+ }>{ Na }^{ + }>{ Mg }^{ 2+ }$
0%
${ Na }^{ + }>{ Li }^{ + }>{ Mg }^{ 2+ }>{ Be }^{ 2+ }$
0%
${ Li }^{ 2+ }>{ Na }^{ + }>{ Mg }^{ 2+ }>{ Be }^{ 2+ }$
0%
${ Mg }^{ 2+ }>{ Be }^{ 2+ }>{ Li }^{ + }>{ Na }^{ + }$

Explanation

The ionic radius in general increases on moving from top to bottom in a group and decreases on moving from left to right in a period.

Hence, correct order is

$\underset { 0.95\mathring { A } }{ { Na }^{ + } } >\underset { 0.68\mathring { A } }{ { Li }^{ + } } >\underset { 0.65\mathring { A } }{ { Mg }^{ 2+ } } >\underset { 0.63\mathring { A } }{ { Be }^{ 2+ } }$

Diagonal relationship is not shown by:

0%
$Li$ and $Mg$
0%
$Be$ and $Al$
0%
$B$ and $Si$
0%
$C$ and $N$

Explanation

$\bf{Explanation-}$

$\bullet$ Diagonal relationship is shown by the elements which belong to the second period and elements which belong to the third period in the periodic table.

$\bullet$ The adjacently present element of the second period and third period show similar characteristics, therefore it is said that they possess a diagonal relationship.

$\bullet$ The elements present in period

$2nd$ and

$3rd$ are shown below.

Here, lithium is in diagonal relationship with magnesium, beryllium is in diagonal relationship with aluminum, boron is in diagonal relationship with silicon, carbon is in the diagonal relationship between phosphorous, nitrogen is in diagonal relationship with Sulphur, oxygen is in diagonal relationship with chlorine.

$\bullet$ As carbon and nitrogen both are in second group elements so they cannot have a diagonal relationship.

$\bf{Conclusion-}$ Hence, correct option is D because

$C$ and

$N$ is not in diagonal relationship.

Which of the following is a false statement?

0%
Sodium oxide is more basic then magnesium oxide
0%
Beryllium oxide is amphoteric.
0%
The thermal stability of beryllium carbonate is more than that of calcium carbonate
0%
Lithium chloride is deliquescent.

Explanation

As we go down the group in the periodic table the thermal stability of the carbonates increases, because down the group, polarisation decreases, due to increase in size of metal. So, thermal stability of

${ BeCO }_{ 3 }$ is less than that of

${ CaCO }_{ 3 }$ .

Which alkaline earth metal compound is volatile?

0%
$Mg_{3}N_{2}$
0%
$Ca_{3}N_{2}$
0%
$Be_{3}N_{2}$
0%
None of the option

Explanation

$Be_{3}N_{2}$ is volatile due to greater tendency of covalent character in

$Be$ and

$N$ atoms. All other nitrides are of ionic nature.

Which of the following substances are formed when lithium is heated in air?

0%
${ Li }_{ 2 }O+Li{ O }_{ 2 }$
0%
${ Li }_{ 2 }{ O }_{ 2 }$
0%
$Li{ O }_{ 2 }$
0%
$Li_2{ O }_{ }+{ Li }_{ 3 }N\quad$

Explanation

$2Li+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow { Li }_{ 2 }O$

$6Li+{ N }_{ 2 }\longrightarrow 2{ Li }_{ 3 }N$

A mixture of

${ Li }_{ 2 }O$ and

${ Li }_{ 3 }N$

Choose the correct answer form the alternatives given.
Which of the following has lowest thermal stability?

0%
$Li_2CO_3$
0%
$Na_2CO_3$
0%
$K_2CO_3$
0%
$Rb_2CO_3$

Explanation

Lithium carbonates are least thermal stable compound which decompose upon heating to give lithium oxide and carbon dioxide.

${ Li }_{ 2 }C{ O }_{ 3 }\ \rightarrow { Li }_{ 2 }O\ +\ C{ O }_{ 2 }$

Choose the correct answer form the alternatives given.
A solution of a compound

$X$ in dilute

$HCl$ on treatment with a solution of

$BaCl_2$ gives a white precipitate of compound

$Y$ which is insoluble in conc.

$HNO_3$ and conc.

$HCl$ . Compound

$X$ imparts golden yellow colour to the flame.

$\underset{(\text{imparts golden yellow colour})}{X (\text{solution in dilute HCl})}+BaCl_2\longrightarrow \underset{white \\ ppt}{Y} \xrightarrow[Conc Hcl]{Conc.HNO_3\\ +} Insoluble$
What are compounds

$X$ and

$Y$ ?

0%
$X$ is $MgCl_2$ and $Y$ is $BaSO_4$
0%
$X$ is $CaCl_2$ and $Y$ is $BaSO_4$
0%
$X$ is $Na_2SO_4$ and $Y$ is $BaSO_4$
0%
$X$ is $MgSO_4$ and $Y$ is $BaSO_4$

Explanation

$\underset{(\text{imparts golden yellow colour})}{X (\text{solution in dilute HCl})}+BaCl_2\longrightarrow \underset{white \\ ppt}{Y} \xrightarrow[Conc Hcl]{Conc.HNO_3\\ +} Insoluble$
Thecompounds

$X$ and

$Y$ are

$Na_2SO_4 + BaCl_2 \rightarrow BaSO_4 + 2NaCl$
(X) (Y)

Choose the correct answer form the alternatives given.
Which of the following statements is not true about alkali metals ?

0%
All alkali metals from oxo salts such as carbonates, sulphates and nitrates.
0%
The basic character of oxides increases down the group.
0%
Carbonates and sulphates of lithium are stable and their stability decreases down the group.
0%
Solubility of carbonates and sulphates increases down the group.

The properties of

$Li$ are similar to those of

$Mg$ . This is because:

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

Explanation

The properties of lithium are similar to those of $Mg$ because they are having diagonal relationship.
The elements having diagonal relationship show similar properties and the reason is because the both of them will have similar electronegativity and polarising power i.e. charge per size ratio of both the elements are nearly the same.

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?

0%
$300ppm$
0%
$350ppm$
0%
$450ppm$
0%
$500ppm$

Which one of the following will not give flame test?

0%
$Ca$
0%
$Ba$
0%
$Sr$
0%
$Be$

Magnesium cation has polarising power close to that of:

0%
$Li^{+}$
0%
$Na^{+}$
0%
$K^{+}$
0%
$Cs^{+}$

Explanation

lithium

$Li^+$

The increasing order of the density of alkali metals :

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

Which of the following alkali metals when burnt in air forms a mixture of oxide as well as nitride?

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

Explanation

The alkali metals tarnish in dry air due to the formation of their oxides which in turn react with moisture to form hydroxides. They burn vigorously in oxygen forming oxides. Lithium forms monoxide

${Li}_{2}O$ , sodium forms peroxide

${Na}_{2}{O}_{2}$ , the other metals form superoxides

${O}^{2-}$ ions.

$4Li+{ O }_{ 2 }\rightarrow 2{ Li }_{ 2 }O$ (normal oxide)

$2Na+{ O }_{ 2 }\rightarrow 2{ Na }_{ 2 }{O}_{2}$ (peroxide)

$M+{ O }_{ 2 }\rightarrow { M }{ O }_{2}$ (superoxide)

where M is

$M=K,Rb,Cs$

In all these oxides the oxidation state of the alkali metal is +1. Lithium shows exceptional behaviour in reacting directly with nitrogen of air to form the nitride,

${ Li}_{ 3 }N$ .

The first element of the groups 1 and 2 are different from other members of the respective groups. Their behaviour is more similar to the second element of the following groups. What is this relationship known as?

0%
Anomalous relationship
0%
Periodic relationship
0%
Diagonal relationship
0%
Chemical relationship

Which of the following oxides is most acidic in nature?

0%
$BaO$
0%
$MgO$
0%
$CaO$
0%
$BeO$

Explanation

As we know that the acidic character of oxides increases across the period while it decreases down the group. Therefore, the acidic character of oxides follows the order:

$BeO>MgO>CaO>BaO$

Therefore,

$BeO$ is most acidic.

The pair of amphoteric oxides is:

0%
$BeO, ZnO$
0%
$Al_2O_3,Li_2O$
0%
$BeO, BO_3$
0%
$BeO, MgO$

Explanation

$BeO$ and

$ZnO$ are amphoteric in nature because they can react both in acidic as well as a basic solution.

Here

$M = Be,\ Zn$

Reaction with acids:

$MO\quad +\quad 2{ H }^{ + }\quad \rightarrow \quad { M }^{ 2+ }\quad +\quad { H }_{ 2 }O$

Reaction with base:

$MO\quad +\quad { H }_{ 2 }O\quad +\quad 2O{ H }^{ - }\quad \rightarrow \quad { [M{ (OH) }_{ 4 }] }^{ 2- }$

Lithium salts are mostly hydrated like

$LiCl.2H_2O$ due to:

0%
maximum ionisation enthalpy
0%
maximum degree of hydration of $Li^+$
0%
maximum hydroscopic nature
0%
maximum chemical reactivity.

Explanation

${ Li }^{ + }$ ion being small in size is surrounded by large no. of water molecules on account of which it has very hydration energy. Hence, it is heavily hydrated and have high degree of hydration.

Which nitrate will decompose to give

$NO_2$ on heating?

0%
$NaNO_3$
0%
$KNO_3$
0%
$RbNO_3$
0%
$LiNO_3$

Explanation

Only

$LiNO_3$ gives

$NO_2$ on heating. All other nitrates give oxygen.

$4LiNO_3 \, \xrightarrow{\Delta} \, 2Li_2O \, + \, 4NO_2 \, + \, O_2.$

$2NaNO_3 \, \xrightarrow{\Delta} \, 2NaNO_2 \, + \, O_2$

Which of the following is not the point of difference between Be and other alkaline earth metals?

0%
It has a tendency to form covalent bonds.
0%
It dissolves in alkalies with evolution of hydrogen.
0%
Its oxides and hydroxides are amphoteric.
0%
Its carbide gives acetylene on hydrolysis

Explanation

$Be_2C$ gives methane on hydrolysis while other carbides give acetylene.

$Be_2C + 4H_2O \rightarrow 3 2Be(OH)_2 + CH_4$

The decreasing order of the second ionization potential of

$Mg,\ Ca$ and

$Ba$ is:

0%
$Mg > Ca > Ba$
0%
$Ca > Ba > Mg$
0%
$Ba > Mg > Ca$
0%
$Mg > Ba > Ca$

Explanation

The ionization potential decreases down the group as the distance between valence electron and nucleus increases. The ionization potential increases after the successive removal of one or more electrons from isolated gaseous atom. Small size cations will have high ionization potential than large size cations.

The decreasing order of second ionization potential is:

$Mg > Ca > Ba$

Which among the following is kinetically inert towards water?

0%
Na
0%
Be
0%
Ca
0%
K

Which of the following does not show diagonal relationship between beryllium and aluminium?

0%
Both $BeO$ and $Al_2O_3$ are amphoteric in nature.
0%
Both beryllium and aluminium form polymetric covalent hydrdes.
0%
Both beryllium and aluminium form nitrides with nitrogen which evolve $NH_3$ with water.
0%
Both metal carbonates are highly stable.

Explanation

$Be$ and

$Al$ show diagonal relation but both of their carbonates are unstable because smaller and more charged metal cations tend to distort the electron cloud of

$CO_3^{2+}$ ions (polarization).

Which of the following does not show the anomalous behaviour of Lithium?

0%
Lithium reacts with nitrogen to form a nitride
0%
Lithium carbonate decomposes on heating
0%
Lithium nitrate gives $NO_2$ on heating
0%
Lithium is the strongest reducing agent

Which is the correct sequence of solubility of carbonates of alkaline earth metals?

0%
$BaCO_3 > SrCO_3 > CaCO_3 > MgCO_3$
0%
$MgCO_3 > CaCO_3 > SrCO_3 > BaCO_3$
0%
$CaCO_3 > BaCO_3 > SrCO_3 > MgCO_3$
0%
$BaCO_3 > CaCO_3 > SrCO_3 > MgCO_3$

Fill up the blanks with appropriate choices.
Lithium and magnesium react slowly with water. Their hydroxides are ________ soluble in water. Carbonates are Li and Mg ________ easily on heating. Both LiCl and

$MgCl_2$ are ________ in entanol and are ________. They crystallise from their aqueous solutions as _________.

0%
more, do not decompose, soluble, hygroscopic, hydrates
0%
less, decompose, soluble, deliquescent, hydrates
0%
freely, sublime, insoluble, deliquescent, anhydrous
0%
freely, decompose, soluble, hygroscopic, crystals

The metal ions (charged particles) that are required for contraction of muscles in human beings and animals are ions of:

0%
calcium
0%
sodium
0%
potassium
0%
iron

Explanation

$Ca^{2+}$ ions are required for contraction of muscles in humans.

Which of the following compounds is formed when sodium burns in excess supply of air ?

0%
Sodium suboxide
0%
Sodium oxide
0%
Sodium peroxide
0%
Sodium superoxide

Cancer is a disease where body cells grow unchecked. A protein found in the body interferes with the growth of cancer cells. It is used for the treatment of cancer. Identify it.

0%
Haemoglobin
0%
Casein
0%
Keratin
0%
Interferon

A metal readily forms its sulphate

$MSO_4$ which is water soluble. It forms its oxide MO which becomes inert on heating. It forms its insoluble hydroxide

$M(OH)_2$ which is soluble in NaOH solution. What would be M?

0%
Be
0%
Ba
0%
Ca
0%
Mg

Explanation

Metal Be forms water soluble

$BeSO_4$ and forms

$BeO$ which on heating turns inert.

$Be$ forms an insoluble hydroxide

$Be(OH)_2$ which is soluble in

$NaOH$ giving sodium berylate

$Na_2BeO_2$

The violet flame shown by potassium in Bunsen flame is due to jumping of the electron from :

0%
1s to 4p
0%
1s to 5p
0%
4p to 4s
0%
5p to 4s

Explanation

On heating an alkali earth metal or its salt, the electrons are excited easily to higher energy levels because of absorption of energy. When these electrons return to their ground states, they emit extra energy in form of radiations which fall in the visible region thereby imparting a characteristic colour to the flame.
The violet flame shown by potassiu in Bunsen flame is due to jumping of the electron from $5p$ to $4s$ .
Hence, option D is correct answer.

Which of the following metals is required as a cofactor by all enzymes utilizing ATP in phosphate transfer?

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

Alkaline earth metals are sparingly soluble in water and their carbonates evolve carbon dioxide on heating. Which of the following is not an alkaline earth metal?

0%
Calcium
0%
Magnesium
0%
Beryllium
0%
Aluminium

Alkali metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously?

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

Explanation

$Li$ reacts with water least vigorously due to the small size and very high hydration energy.

Dehydration of hydrates of halides of calcium, barium and strontium i.e.,

$CaCl_2.6H_2O,BaCl_2.2H_2O,SrCl_2.2H_2O$ can be achieved by heating. These become wet on keeping in the air. Which of the following statements is correct about these halides?

0%
The act as dehydrating agents.
0%
They can absorb moisture from air.
0%
They have tendency to from hydrate which decreases from calcium to barium.
0%
All of the above

Explanation

Halides of calcium, barium and strontium act as dehydrating agent as they are hygroscopic in nature. They absorb moisture. Also they have tendency to form hydrate which decreases from

$Ca^{2+}$ to

$Sr^{2+}$ due to increase in size and decrease in polarization power.

Which of the following is not a similarity of beryllium with aluminium?

0%
It becomes passive when treated with conc. $HNO_3$ .
0%
It forms polymeric covalent hydrides.
0%
Carbonate of Be is extremely stable.
0%
Salts of Be do not impart colour to the flame.

Explanation

Beryllium shows resemblance with its diagonally opposite element aluminium.

Points of similarity are-

Both metals have a tendency to form covalent bonds. Eg; Chlorides of both are being covalent are being soluble in organic solvents.
Both $BeCl_2$ and $AlCl_3$ act as Lewis acids and are used as Friedal Kraft's catalyst.
These two elements have the same electronegativity and polarizing power i.e. charge per radius ration of their ions are very similar.
They form polymeric covalent hydrides.
They become passive when treated with $conc.HNO_3$
Salts of Be do not impart colour to the flame.
But, the stability of Carbonate of $Be$ is not similar to carbonate of $Al$ .Hence, option C is the correct answer.

Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?

0%
$MgCO_3$
0%
$CaCO_3$
0%
$SrCO_3$
0%
$BaCO_3$

Explanation

$BaCO_3$ is most thermally stable as the size of

$Ba^{2+}$ is big due to which it is having low polarising power and thus cannot polarize oxygen electrons due to which carbonates of large cations are stable.

CBSE Questions for Class 11 Medical Chemistry The S-Block Elements Quiz 7 - 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 7 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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