Assertion : s-block elements do not occur free in nature Reason: s-block elements are highly electropositive in nature. If both the assertion and the reason are true and the reason is a correct explanation of the assertion If both the assertion and reason are true but the reason is not a correct explanation of the assertion If the assertion is true but the reason is false If both the assertion and reason are false

Both A and R are true and R is the correct explanation of A.

Both A and R are true, but R is not the correct explanation of A.

Which of the following statements is false?

Ca 2+ ions are not important in maintaining the regular beating of the heart

Ca 2+ ions are important in blood clotting

Mg 2+ ions are important in the green parts of plants

Mg 2+ ions form a complex with ATP

Chemistry - Sblock Elements - Quiz-6

The correct order of increasing lattice energy of the metallic compounds is –

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NaCl < CaO < NaI < BaO
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NaI < NaCl < BaO < CaO
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NaCl < NaI < BaO < CaO
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NaI < NaCl < CaO < BaO

Which alkali metal has the lowest melting point and exists as a liquid at 30 degree temp–

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Na
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K
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Rb
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Cs

The boiling point of calcium is abnormally high as compared to magnesium because-

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In calcium d-orbital forms a weak metallic bond
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In calcium p-orbital forms a weak metallic bond
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In calcium d-orbital forms a strong metallic bond
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In calcium s-orbital forms a strong metallic bond

The decreasing order of II ionisation energy of K, Ca, and Ba is –

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K > Ca > Ba
(2) Ca > Ba > K
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2
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Ba > K > Ca
(4) K > Ba > Ca
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4

Two metals X and Y form covalent halides. Both halides can act as Lewis acids and a catalyst in Friedel Crafts reaction. Halide of X is polymer in the solid state and a dimer in the vapour state which decomposes to monomer at 1200 K. However, halide of Y is a dimer in vapour state and becomes ionic in polar solvent. X and Y are respectively.

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Be, Al
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Al, Be
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Be, Ca
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Mg, Ca

Which of the following compounds decomposes on heating similar to $L i N O_{3}$ .

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$B a {(N O_{3})}_{2}$
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$S r {(N O_{3})}_{2}$
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$M g {(N O_{3})}_{2}$
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All

Solubility of sulphates in water decreases from $M g S O_{4}$ to $B a S O_{4}$ . It is due to the fact that –

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Ionic nature increases
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Size of $M^{2 +}$ ion increases
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Lattice energy decrease
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Hydration enthalpy of $M^{2 +}$ ions decreases

In the Solvay process of manufacture of sodium carbonate, the raw materials used are :

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Aqueous NaOH, $N H_{3}$ and $C O_{2}$
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Molten NaOH, $N H_{3}$ and CO
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Brine NaCl, $N H_{3}$ and CO
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Brine NaCl, $N H_{3}$ and $C O_{2}$

A blue colored solution of an alkali metal in liq NH₃ is due to the presence of -

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$M^{-}$ atoms.
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$M^{+}$ ions .
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Solvated anions .
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Solvated electrons.

Alkali metal ions are-

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Diamagnetic and coloured.
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Diamagnetic and colourless.
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Paramagnetic and coloured.
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Paramagnetic and colourless.

A compound X on heating gives a colourless gas. The residue is dissolved in water to obtain Y. Excess $C O_{2}$ is bubbled through an aqueous solution of Y, and Z is formed. Z on gentle heating gives back X. The compound X is-

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${CaCO}_{3}$
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${Na}_{2} {CO}_{3}$
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${CaSO}_{4} . 2 H_{2} O$
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$K_{2} {CO}_{3}$

Magnesia can be prepared by -

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Burning Mg in air.
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Heating hydroxide, nitrate, sulphate or carbonate of magnesium.
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Heating Mg in steam.
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All of the above.

A compound insoluble in acetic acid is -

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Calcium oxide.
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Calcium carbonate.
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Calcium oxalate.
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Calcium hydroxide.

Assertion : LiF is almost insoluble in water

Reason : LiCl is soluble not only in water but also in acetone.

If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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1
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2
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3
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4

Assertion : s-block elements do not occur free in nature

Reason: s-block elements are highly electropositive in nature.

If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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Both A and R are true and R is the correct explanation of A.
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Both A and R are true, but R is not the correct explanation of A.
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A is true, but R is false.
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Both A and R are false.

Assertion : Potassium and caesium are useful as electrodes in photoelectric cells.

Reason : Potassium and caesium, when irradiated with light, the light energy absorbed is sufficient to eject out the electron from an atom.

If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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1
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2
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3
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4

Assertion : The alkaline earth metals have much higher melting and boiling points than those of the alkali metals.

Reason : The melting and boiling points of alkaline earth metal do not vary in a regular fashion.

If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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1
0%
2
0%
3
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4

Assertion : The ionisation enthalpies of alkaline earth metals are fairly low.

Reason : In general, the low ionisation enthalpies of alkaline earth metals are due to large size of their atoms.

If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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1
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2
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3
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4

Both Be and Al become passive on reaction with concentrated nitric acid due to:

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The non-reactive nature of the metal.
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The non-reactive nature of the acid.
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The formation of an inert oxide layer on the surface of the metals
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None of these.

$(Yellow ppt) \overset{K_{2} {CrO}_{4}}{\leftarrow} X \overset{dil . HCl}{\to} (Yellow ppt) + Z ↑ (pungent smelling gas)$

If X gives a green flame test, then X is:

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${MgSO}_{4}$
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${BaS}_{2} O_{3}$
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${CuSO}_{4}$
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${PbS}_{2} O_{3}$

The pair of compounds, that cannot exist together in a solution is -

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${NaHCO}_{3} and NaOH$
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${Na}_{2} {CO}_{3} and NaOH$
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${NaHCO}_{3} and {Na}_{2} {CO}_{3}$
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${NaHCO}_{3} and H_{2} O$

A paramagnetic compound among the following is -

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$K_{2} O$
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$K_{2} O_{2}$
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${Na}_{2} O_{2}$
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${RbO}_{2}$

The commercial method of preparation of potassium by reduction of molten KCl with metallic sodium at 850°C is based on the fact that -

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Potassium is solid and sodium distils off at 850 °C.
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Potassium is more volatile and distils off thus shifting the reaction forward.
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Sodium is more reactive than potassium at 850 °C.
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Sodium has less affinity to chloride ions in the presence of potassium ions.

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Practice Chemistry Quiz Questions and Answers

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Practice Chemistry Quiz Questions and Answers

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