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Chemistry M.C.Q (1 Marks)

The s-block Elements · UP Board (UPMSP) STD 11 Science (UPMSP - English Medium). 191 questions.

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M.C.Q (1 Marks)

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50 questions · auto-graded multiple-choice test.

MCQ 11 Mark
The metal which gives brick red colour in flame test is:
  • A
    Barium
  • ✓
    Calcium
  • C
    Strontium
  • D
    Radium
Answer
Correct option: B.
Calcium
Calcium metal gives brick red color in flame. It is due to the excitation of electrons by the thermal energy which is then followed by de $-$ excitation of an electron to ground state along with the liberation of light in the visible range.
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MCQ 21 Mark
Which of the following is a false statement?
  • A
    Sodium oxide is more basic then magnesium oxide
  • B
    Beryllium oxide is amphoteric.
  • ✓
    The thermal stability of beryllium carbonate is more than that of calcium carbonate
  • D
    Lithium chloride is deliquescent.
Answer
Correct option: C.
The thermal stability of beryllium carbonate is more than that of calcium carbonate
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 $\ce{BeCO_3}$​ is less than that of $\ce{CaCO_3}$​.
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MCQ 31 Mark
Which of the following forms the most basic hydroxide?
  • A
    $Cu$
  • B
    $Al$
  • ✓
    $Na$
  • D
    $Zn$
Answer
Correct option: C.
$Na$
As sodium has highest oxidation potential among all. So it has highest tendency for oxidation reaction and it forms most basic hydroxide.
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MCQ 41 Mark
The least electropositive alkali metal is:
  • A
    Sodium
  • ✓
    Lithium
  • C
    Potassium
  • D
    Caesium
Answer
Correct option: B.
Lithium
Among alkali metals, the ionization energy decreases from $Li$ to $Cs$. Hence the electropositive character increases from $Li$ to $Cs$. Hence among alkali metals, $Li$ is the least electropositive metal.
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MCQ 51 Mark
Which of the following element is present in excess amount in human bones and teeth?
  • A
    Sodium.
  • B
    Potassium.
  • ✓
    Calcium.
  • D
    Carbon.
Answer
Correct option: C.
Calcium.
Calcium is present in human body in bones and teeth. About $99\%$ of body calcium is present in bones and teeth.
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MCQ 61 Mark
Suspension of slaked lime in water is known as:
  • A
    Lime water.
  • B
    Quick lime.
  • ✓
    Milk of lime.
  • D
    Aqueous solution of slaked lime.
Answer
Correct option: C.
Milk of lime.
$\text{CaO}+\text{H}_2\text{O}\xrightarrow{\ \ \ \ }\text{Ca}(\text{OH})_2+\text{Heat}\\\text{Quick lime}\ \ \ \ \ \ \ \ \ \ \ \ \ \text{Slaked lime}$
This process is known as slaking of lime.
The paste of lime in water $($i.e.; suspension$)$ is called milk oi lime while the filtered and clear solution is known as lime water.
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MCQ 71 Mark
Alkali metals are generally silvery white but beryllium and magnesium appears to be :
  • A
    Reddish.
  • ✓
    Grayish.
  • C
    Yellowish.
  • D
    None of these.
Answer
Correct option: B.
Grayish.
Alkaline earth metals are generally silvery white but $Be$ and $Mg$ appears tobe greyish in colour.
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MCQ 81 Mark
Which of the following trace elements is present in virtually all potable water?
  • A
    Lead
  • ✓
    Sodium
  • C
    Manganese
  • D
    Mercury
Answer
Correct option: B.
Sodium
There are a variety of trace elements present in virtually all potable water, some of which play a role in metabolism. For example, sodium, potassium and chloride are common chemicals found in small quantities in most waters, and these elements play a role in body metabolism.
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MCQ 91 Mark
$Be$ and $Al$ resemble in the following but not in :
  • A
    both form electron decient hydrides
  • B
    both are rendered passive by $\ce{HNO_3}$​
  • C
    both form amphoteric oxides
  • ✓
    both have sp$-$hybridisation in their compounds
Answer
Correct option: D.
both have sp$-$hybridisation in their compounds
Both form electron deficient hydrides due to incomplete octet.
Both form amphoteric oxides as their oxides react with both acid and base.
Be have sp$-$hybridization and $Al$ have $sp_2-$ hybridization in their compounds.
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MCQ 101 Mark
Percentage of $\ce{CaO}$ present in Portland cement is :
  • ✓
    $50-60\%$
  • B
    $70-80\%$
  • C
    $90\%$
  • D
    $40\%$
Answer
Correct option: A.
$50-60\%$
The average composition of Portland cement is $\mathrm{Cao}, 50 \%-60 \%, \mathrm{SiO}_2, 20-25 \% ; \mathrm{Al}_2 \mathrm{O}_3, 5-10 \% ; \mathrm{MgO}, 2-3 \% ; \mathrm{Fe}_2 \mathrm{O}_3, 1-$ $2 \%$ and $\mathrm{SO}_3, 1-2 \%$.
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MCQ 111 Mark
Powder of beryllium burns in air frequently to produce:
  • A
    $\ce{BeO}$
  • B
    $\ce{Be_3N_2}$
  • C
    $\ce{Be_2O}$
  • ✓
    Both $(a)$ and $(b)$
Answer
Correct option: D.
Both $(a)$ and $(b)$
Powdered beryllium burns brilliantly in air to give $\ce{BeO}$ and $\ce{Be_3N_2. Be_2O}$ is not formed as both $Be$ and $O$ have valency equal to $2$.
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MCQ 121 Mark
Potassium ions are most abundant in the cell fluid. Which of the following reaction is performed by the potassium ion present in them?
  • A
    They perform oxidation of glucose to $\ce{ATP}$.
  • B
    They perform nerve signals transmission.
  • ✓
    Both $(a)$ and $(b)$ are true.
  • D
    None of the above.
Answer
Correct option: C.
Both $(a)$ and $(b)$ are true.
$K^+$ ions present in fluid of cell are used in the oxidation of glucose to produce $\ce{ATP}$ and transmission of nerve signals.
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MCQ 131 Mark
Which of the following is the nearest base?
  • A
    $\ce{Ca(OH)_2}$
  • B
    $\ce{KOH}$
  • ✓
    $\ce{LiOH}$
  • D
    $\ce{Sr(OH)_2}$
Answer
Correct option: C.
$\ce{LiOH}$
$\ce{LiOH}$ is nearest base because li has least tendency to lose election.
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MCQ 141 Mark
The second ionisation enthalpy of the alkaline earth metals are smaller than that of corresponding group I metals. This is due to:
  • A
    Large size of alkali metals.
  • ✓
    Stable configuration of alkali metal ions.
  • C
    Small size of alkaline earth metals.
  • D
    Stable configuration of alkaline earth metal monocation.
Answer
Correct option: B.
Stable configuration of alkali metal ions.
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MCQ 151 Mark
The product recycled during Solvay process is$/$ are:
  • A
    $\ce{CO_2}$
  • B
    $\ce{NH_3}$
  • C
    $\ce{NaCl}$
  • ✓
    Both $(a)$ and $(b)$
Answer
Correct option: D.
Both $(a)$ and $(b)$
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MCQ 161 Mark
Considering their electron affinities, do you think the alkali metals can form an anion like $M−$, where $M$ represents an alkali metal?
  • A
    Yes, due to stable $ns^1$ configuration.
  • B
    No, due to stable $ns^1$ configuration.
  • ✓
    Yes, due to stable $ns^2$ configuration.
  • D
    No, due to unstable $ns^2$ configuration.
Answer
Correct option: C.
Yes, due to stable $ns^2$ configuration.
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MCQ 171 Mark
Which one of the following has magnesium?
  • A
    Vitamin $\mathrm {B}_{12}$
  • ✓
    Chlorophyll
  • C
    Haemocyanin
  • D
    Carbonic anhydrase
Answer
Correct option: B.
Chlorophyll
$Mg$ is present in chlorophyll which is a green pigment and is used in photosynthesis in green plants.
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MCQ 181 Mark
Diagonal relationship is due to:
  • A
    identical ionization potential
  • B
    identical electron negativity
  • ✓
    identical sizes of ions
  • D
    same valence shell configuration
Answer
Correct option: C.
identical sizes of ions
The diagonal relationship is due to identical sizes of ions.
On moving rightward a period of the periodic table, the size of the atoms decreases, and on moving down a group the size of the atoms increases. Similarly, on moving rightward a period, the elements become more electronegative, whereas on moving down the group the element becomes more positive. These two factors work in opposite direction. Hence the elements that are present diagonally to each other have similar properties like atomic size, electronegativity, density, chemical properties of compounds.
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MCQ 191 Mark
Several sodium compounds find use in industries. Which of the following compounds are used for textile industry?
  • ✓
    $\ce{Na_2CO_3}$
  • B
    $\ce{NaHCO_3}$
  • C
    $\ce{NaOH}$
  • D
    $\ce{NaCl}$
Answer
Correct option: A.
$\ce{Na_2CO_3}$
$\ce{Na_2CO_3}$ is used in manufacture of soap powders, In laundry and textile industry. $\ce{NaoH}$ is used in soap industry, Paper industry.
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MCQ 201 Mark
The reducing power of a metal depends on various factors. Suggest the factor which makes $Li$, the strongest reducing agent in aqueous solution.
  • A
    Sublimation enthalpy.
  • B
    Ionisation enthalpy.
  • ✓
    Hydration enthalpy.
  • D
    Electron$-$gain enthalpy.
Answer
Correct option: C.
Hydration enthalpy.
Lithium has highest hydration enthalpy which accounts for its high negative $E^{\circ}$ value and its high reducing power.
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MCQ 211 Mark
What is used in synthesis of chlorophyll In $C_4$ plants?
  • ✓
    Sodium
  • B
    Iron
  • C
    Potassium
  • D
    Aluminium
Answer
Correct option: A.
Sodium
In $C_4$ plants, sodium is a micronutrient that aids in metabolism, specifically in regeneration of phosphoenolpyruvate $($involved in the biosynthesis of various aromatic compounds, and in carbon fixation$)$ and synthesis of chlorophyll.
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MCQ 221 Mark
In the synthesis of sodium carbonate, the recovery of ammonia is done by treating $\ce{NH_4Cl}$ with $\ce{Ca(OH)_2}$. The by$-$product obtained in this process is:
  • ✓
    $\ce{CaCl_2}$
  • B
    $\ce{NaCl}$
  • C
    $\ce{NaOH}$
  • D
    $\ce{NaHCO_3}$
Answer
Correct option: A.
$\ce{CaCl_2}$
Sodium carbonate is synthesised by Solvay or ammonia soda process. The reactions involved are:
$\text{NH}_3+\text{H}_2\text{O}+\text{CO}_2\xrightarrow{\ \ \ \ }\text{NH}_4\text{HCO}_3\\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \text{Ammonium bicarbonate}$
$\text{NaCl}+\text{NH}_4\text{HCO}_3\xrightarrow{\ \ \ \ }\text{NaHCO}_3\downarrow+\text{NH}_4\text{Cl}\\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \text{Sodium bicarbonate}$
$2\text{NaHCO}_3\xrightarrow{\ \ \Delta\ \ }\text{Na}_2\text{CO}_3+\text{H}_2\text{O}+\text{CO}_2\\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \text{Sodium carbonatre}$
$\ce{NH_3}$ is recovered from $\ce{NH_4HCO_3}$ and $\ce{NH_4Cl
}$ formed during the reaction.
$\text{NH}_4\text{HCO}_3\xrightarrow{\ \ \text{Heat}\ \ }\text{NH}_3+\text{H}_2\text{O}+\text{CO}_2$
$2\text{NH}_4\text{Cl}+\text{Ca(OH)}_2\xrightarrow{\ \ \ \ }2\text{NH}_3+\text{CaCl}_2+2\text{H}_2\text{O}\\\text{Ammonium chloride}\ \ \ \ \ \ \text{Ammonia}\ \text{Calcium chloride}$
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MCQ 231 Mark
Which among the following is kinetically inert towards water?
  • A
    $Na$
  • ✓
    $Be$
  • C
    $Ca$
  • D
    $K$
Answer
Correct option: B.
$Be$
$Na, K$ and $Ca$ decompose water by evolving hydrogen gas. However Be does not react with water even when red hot. Its protective oxide layer survives even at high temperature.
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MCQ 241 Mark
Metals having $ns1$ as the valence electronicconfiguration :
  • A
    act as strong oxidizing reagent
  • B
    are highly electronegative
  • ✓
    are highly electropostive
  • D
    have a first ionization potential of more than $10\  eV/atom$
Answer
Correct option: C.
are highly electropostive
Alkali metals have valence electronic configuration $ns1.$
They are highly electropositive elements with low ionization energies.
They act as strong reducing agents.
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MCQ 251 Mark
Among the alkali metals, the metal with the highest ionisation potential is:
  • A
    $Na$
  • ✓
    $Li$
  • C
    $Rb$
  • D
    $Cs$
Answer
Correct option: B.
$Li$
On moving down the group, the atomic number of alkali metals increases. This increases the atomic size, nuclear charge and the screening effect. Hence the ionization energies decrease from lithium to caesium.
Hence, lithium has the highest ionization enthalpy among the alkali metals.
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MCQ 261 Mark
The low melting point of alkali metals is due to:
  • A
    Weak metallic bonding.
  • B
    Presence of only one valence electron.
  • C
    Lower density.
  • ✓
    Both $(a)$ and $(b)$.
Answer
Correct option: D.
Both $(a)$ and $(b)$.
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MCQ 271 Mark
The metal ions $($charged particles$)$ that are required for contraction of muscles in human beings and animals are ions of:
  • ✓
    calcium
  • B
    sodium
  • C
    potassium
  • D
    iron
Answer
Correct option: A.
calcium
$\ce{Ca^{2+}}$ ions are required for contraction of muscles in humans.
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MCQ 281 Mark
Nitrolim is a:
  • A
    Mixture of calcium carbide and nitrogen
  • ✓
    Mixture of calcium cyanamide and carbon
  • C
    Mixture of calcium cyanide and carbon
  • D
    Mixture of $\ce{NH_4​CN}$ and $\ce{CaCN}$
Answer
Correct option: B.
Mixture of calcium cyanamide and carbon
When nitrogen is passed over calcium carbide at a suitable high temperature, we get a mixture called nitrolim which is a nitrogenous fertilizer, which is a mixture of calcium cyanamide and carbon.
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MCQ 291 Mark
Metals form basic hydroxides. Which of the following metal hydroxides is the least basic?
  • A
    $\ce{Mg(OH)_2}$
  • B
    $\ce{Ca(OH)_2}$
  • C
    $\ce{Sr(OH)_2}$
  • ✓
    $\ce{Ba(OH)_2}$
Answer
Correct option: D.
$\ce{Ba(OH)_2}$
As the ionization enthalpy increases from $\text{Mg}\xrightarrow{}\text{Ba},$ the $M-O$ bond becomes weaker and weaker down the group and hence basicity increases down the group. Thus, $\ce{Mg(OH)_2}$ is least basic.
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MCQ 301 Mark
Which of the following physical property of beryllium makes it perfect aerospace material?
  • A
    High thermal conductivity
  • B
    Low density
  • ✓
    Both $A$ and $B$
  • D
    Beryllium is not suitable for aerospace mateerial
Answer
Correct option: C.
Both $A$ and $B$
It should be light to make aerospace material.
Beryllium has low density and also has high thermal conductivity.
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MCQ 311 Mark
A substance which gives brick red colour in flame test and breaks down on heating to give oxygen and a brown gas is :
  • A
    Magnesium nitrate
  • ✓
    Calcium nitrate
  • C
    Barium nitrate
  • D
    Strontium nitrate
Answer
Correct option: B.
Calcium nitrate
Calcium nitrate gives brick red colour in flame test and breaks down on heating to give oxygen and a brown gas $\ce{(NO2​)}$.
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MCQ 321 Mark
Which of the carbonates given below is unstable in air and is kept in $\ce{CO_2}$ atmosphere to avoid decomposition.
  • A
    $\ce{BeCO_3}$
  • B
    $\ce{MgCO_3}$
  • C
    $\ce{CaCO_3}$
  • ✓
    $\ce{BaCO_3}$
Answer
Correct option: D.
$\ce{BaCO_3}$
Due to least electropositive character or least basicity of $\ce{Be,BeCO_3}$ is less stable and hence decomposes to give $\ce{BeO}$ and $\ce{CO_2}$.
$\text{BeCO}_3\xrightarrow{}\text{BeO}+\text{CO}_2$
Since the decomposition reaction is reversible, therefore, to increase the stability of $\ce{BeCO_3}$ or to reverse the above equilibrium, $\ce{BeCO_3}$ is kept in an atmosphere of $\ce{CO_2}$.
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MCQ 331 Mark
Which of the following statement is true regarding alkaline earth metals?
  • A
    Beryllium and barium compounds are poisonous in nature
  • B
    Beryllium shows diagonal relationship with aluminium
  • C
    Beryllium salts impart yellow colour to flame
  • ✓
    Both $A$ and $B$
Answer
Correct option: D.
Both $A$ and $B$
Due to comparatively same size as aluminium, Beryllium show diagonal relationship with aluminium. Same charge/ size ratio.
Due to the high reactivity of metals, water $-$ soluble compounds of $Be$ and $Ba$ are poisonous.
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MCQ 341 Mark
Along the group of alkali metals, the density:
  • A
    Decreases from top to bottom.
  • ✓
    Increases from top to bottom.
  • C
    Remains the same.
  • D
    Follow a irregular trend.
Answer
Correct option: B.
Increases from top to bottom.
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MCQ 351 Mark
The alkali metal halide soluble in pyridine is:
  • A
    $\text{NaCl}$
  • ✓
    $\text{LiCl}$
  • C
    $\text{KCl}$
  • D
    $\text{Csl}$
Answer
Correct option: B.
$\text{LiCl}$
$\text{LiCl}$ is soluble in pyridine because it is covalent.
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MCQ 361 Mark
What is the main reason of diagonal relationship between lithium and magnesium?
  • A
    Electronegativity remains constant the same on moving parallel.
  • ✓
    Electronegativity remains constant the same on moving horizontally.
  • C
    Electronegativity remains constant the same on moving diagonally.
  • D
    Electronegativity remains constant the same on moving vertically.
Answer
Correct option: B.
Electronegativity remains constant the same on moving horizontally.
The diagonally opposite elements possess almost similar electronegativities and there fore almost similar electropositive character.
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MCQ 371 Mark
Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?
  • A
    $\ce{CaSO_4}$​
  • ✓
    $\ce{BeSO_4}$
  • C
    $\ce{BaSO_4}$
  • D
    $\ce{SrSO_4}$​
Answer
Correct option: B.
$\ce{BeSO_4}$
Hydration energy decreases down the group, whereas lattice energy remains almost constant.
Thus, hydration enthalpy is higher than the lattice enthalpy in case of $\ce{BeSO_4}$​.
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MCQ 381 Mark
Which of the following element$(s)$ is used as electrode$(s)$ in photoelectric cells?
  • A
    Sodium.
  • B
    Caesium.
  • C
    Potassium.
  • ✓
    Both $(b)$ and $(c).$
Answer
Correct option: D.
Both $(b)$ and $(c).$
When $Cs$ and $K$ are irradiated with light, the light energy absorbed may be sufficient to make the metal atom lose an electron. This property makes $Cs$ and $K$ useful as electrodes in photoelectric cell.
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MCQ 391 Mark
In certain matters, lithium differs from other alkali metals, the main reason for this is:
  • ✓
    Small size of lithium atom and $Li^+$ ion
  • B
    Extremely high electro positivity of $Li$
  • C
    Greater hardness of $Li$
  • D
    Hydration of $Li^+$ ion
Answer
Correct option: A.
Small size of lithium atom and $Li^+$ ion
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MCQ 401 Mark
As the alkaline earth metals $($except Be$)$ tend to lose their valence electrons readily. They act as:
  • A
    Weak oxidizing agents.
  • B
    Weak reducing agents.
  • C
    Strong oxidizing agents.
  • ✓
    Strong reducing agents.
Answer
Correct option: D.
Strong reducing agents.
Reducing agent is a substance that tends to bring about reduction by being oxidized and losing electrons
As the alkaline earth metals $($except Be$)$ tend to lose their valence electrons readily. They act as strong reducing agents.
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MCQ 411 Mark
The main pigment for the absorption of light in plants is chlorophyll which contains:
  • ✓
    $Mg$
  • B
    $Mn$
  • C
    $Ca$
  • D
    $Fe$
Answer
Correct option: A.
$Mg$
Main pigment for the absorption of light in plant is chlorophyll which contains $Mg$.
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MCQ 421 Mark
Solvay process is used in the preparation of:
  • ✓
    Sodium carbonate.
  • B
    Potassium carbonate.
  • C
    Caesium carbonate.
  • D
    Rubidium carbonate.
Answer
Correct option: A.
Sodium carbonate.
Generally Solvay process is used in the preparation of sodium carbonate.
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MCQ 431 Mark
Which of the following compounds is not involved in Solvay process?
  • ✓
    $\mathrm{NaNO}_3$
  • B
    $\left(\mathrm{NH}_4\right) 2 \mathrm{CO}_3$
  • C
    $\mathrm{NH}_4 \mathrm{Cl}_3$
  • D
    $\mathrm{NH}_4 \mathrm{HCO}_3$
Answer
Correct option: A.
$\mathrm{NaNO}_3$
Chemical reactions involved in Solvay process are as follows
$2\text{NH}_3+\text{H}_2\text{O}+\text{CO}_2\xrightarrow{ \ \ \ \ \ \ \ \ \ }(\text{NH}_4)_2\text{CO}_3$
$2(\text{NH}_4)_2\text{CO}_3+\text{H}_2\text{O}+\text{CO}_2\xrightarrow{ \ \ \ \ \ \ \ \ \ }2\text{NH}_4\text{HCO}_3$
$(\text{NH}_4)\text{HCO}_3+\text{NaCl}\xrightarrow{ \ \ \ \ \ \ \ \ \ }\text{NH}_4\text{Cl}+\text{Na}\text{HCO}_3$
Here, $\mathrm{NaNO}_3$ does not involve in any chemical reaction.
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MCQ 441 Mark
Alkaline earth metals have only positive oxidation state. This is due to their:
  • A
    High melting points
  • B
    High electronegativity
  • C
    Softness
  • ✓
    Low ionization potential
Answer
Correct option: D.
Low ionization potential
The alkaline earth metals have very low ionization energies. So, they easily lose electrons to form positively charged ions $($cations$)$. 
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MCQ 451 Mark
The activity of alkaline earth metals as reducing agent :
  • A
    decreases from $Be$ to $Ba$
  • ✓
    increases from $Be$ to $Ba$
  • C
    increase from $Be$ to $Ca$ and decreases from $Ca$ to $Ba$
  • D
    decreases from $Be$ to $Ca$ and increases from $Ca$ to $Ba$
Answer
Correct option: B.
increases from $Be$ to $Ba$
Alkaline earth metals configuration: $ns^2$
So, they have tendency to loose electron so they are reducing agents.
As we move down, electronegativity decreases so reducing nature increases.
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MCQ 461 Mark
What is requirement for sodium in milligrams per day?
  • A
    $400$
  • B
    $500$
  • ✓
    $600$
  • D
    $700$
Answer
Correct option: C.
$600$
The daily requirement of sodium is $600\  mg.$
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MCQ 471 Mark
Which of the following compounds are readily soluble in water?
  • ✓
    $\ce{BeSO_4}$
  • B
    $\ce{MgSO_4}$
  • C
    $\ce{BaSO_4}$
  • D
    $\ce{SrSO_4}$
Answer
Correct option: A.
$\ce{BeSO_4}$
Solubility decreases down the group because hydration enthalpy decreases more rapidly than lattice enthalpy. Thus, $\ce{BeSO4}$ and $\ce{MgSO4}$ are soluble.
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MCQ 481 Mark
Alkali metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously?
  • A
    $Li$
  • B
    $Na$
  • C
    $K$
  • ✓
    $Cs$
Answer
Correct option: D.
$Cs$
$Li$ has very high enthalpy of hydration, therefore the reaction between $Li$ and water is highly exothermic but the energy evolved is consumed in fusion, vaporation and ionisation as a result reaction with water proseeds slowly.
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MCQ 491 Mark
The function of sodium pump is biological process operating in each and every cell of the animals. Which of the following biological important ions is also a constituent of this pump.
  • A
    $ \mathrm{Ca}^{2+}$
  • B
    $ \mathrm{Mg}^{2+} $
  • ✓
    $ \mathrm{K}^{+} $
  • D
    $ \mathrm{Fe}^{2+}$
Answer
Correct option: C.
$ \mathrm{K}^{+} $
$ \mathrm{K}^{+} $ are also present in sodium pump which operates across cell membranes. Calcium carbide and carbon monoxide.
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MCQ 501 Mark
Which element has high concentration in plants, as compared to sodium?
  • ✓
    Potassium
  • B
    Calcium
  • C
    Silicon
  • D
    none
Answer
Correct option: A.
Potassium
Plants need a small amount but high concentration of $K$ for specific functions in the cytoplasmand a major portion $(90\%)$ of it is localized in vacuoles, where it acts as an osmoticum. Maintenance can be achieved by other cation like sodium too.
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