CBSE Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 11 - MCQExams.com

Correct match is:
  • Ordinary form of borax $$: Na_2B_4O_7 \cdot 5H_2O$$
  • Colemanite $$: Ca_2B_6O_{11} \cdot 5H_2O$$
  • Boronatrocalcite $$: 2Mg_3B_8O_{15} \cdot MgCl_2$$
  • Octahedral form of borax $$: Na_2B_4O_7 \cdot 10H_2O$$
Aqueous solutions of borax acts as a buffer because:
  • it contains weak acid and its salt with strong base
  • it contains tribasic acid and strong base
  • it contains number of neutral water molecules
  • none of the above
Boron does not form $${B}^{3+}$$ cation easily. It is due to
  • energy required to form $${B}^{3+}$$ ion is very high 
  • Boron is non-metal
  • Boron is semi-metal
  • none of the above
Electron affinity of:
  • carbon is greater than oxygen
  • sulphur is higher than oxygen
  • chlorine is higher than bromine
  • chlorine is higher than fluorine
Which of the following is most stable?
  • $$Pb^{2+}$$
  • $$Ge^{2+}$$
  • $$Si^{2+}$$
  • $$Sn^{2+}$$
Oxidation number of carbon in $${H}_{2}{C}_{2}{O}_{4}$$ is
  • $$+4$$
  • $$+3$$
  • $$+2$$
  • $$-2$$
The stable compound in $$+1$$ oxidation state are formed by:
  • $$B$$
  • $$Al$$
  • $$Tl$$
  • $$Ga$$
$$Tl I_3$$ is an ionic compound which furnishes the following ions:
  • $$Tl^{3+}$$ and $$I_3^-$$
  • $$Tl^{3+}$$ and $$I^-$$
  • $$Tl^{+}$$ and $$I^-$$
  • $$Tl^{+}$$ and $$I_3^-$$
Which of the following halides is most acidic?
  • $$BCl_3$$
  • $$SbCl_3$$
  • $$BiCl_3$$
  • $$CCl_4$$
Outermost configuration of two $$p-$$ block elements $$A$$ and $$B$$ are $$ns^{2}np^{1}$$ and $$ns^{2}np^{6}$$ respectively. The elements are if $$n=4$$;
  • $$A=Ga, B=Xe$$
  • $$A=In, B=Xe$$
  • $$A=Ga, B=Kr$$
  • $$A=Zn, B=Kr$$
While reviewing the third row elements is periodic table, point out the correct statement:
  • sodium has the largest size
  • chlorine has the maximum electronegativity
  • first ionisation potential of $$Mg >$$ first ionisation potential aluminium
  • chlorine is the strongest reducing agent
Oxidation number of $$C$$ in $${C}_{6}{H}_{12}{O}_{6}$$ is
  • $$+6$$
  • $$-6$$
  • $$0$$
  • $$+4$$
The oxidation number of carbon in $${CH}_{2}O$$ is
  • $$-2$$
  • $$+2$$
  • $$0$$
  • $$+4$$
The chemical name of borax is
  • Sodium orthoborate
  • Sodium metaborate
  • Sodium tetraborate
  • Sodium tetraborate decahydrate
Oxidation number of carbon in $${CH}_{3}-Cl$$ is
  • $$-3$$
  • $$-2$$
  • $$-1$$
  • $$0$$
The oxidation number of carbon in $${CH}_{2}{Cl}_{2}$$ is
  • $$0$$
  • $$+2$$
  • $$-2$$
  • $$+4$$
Oxidation state of elemental carbon is
  • $$0$$
  • $$1$$
  • $$2$$
  • $$3$$
Thallium shows different oxidation states because 
  • it is a transition metal
  • of inert-pair effect
  • of its high reactivity
  • of its amphoteric character
How many ionisation energies can carbon have
  • $$1$$
  • $$2$$
  • $$4$$
  • $$6$$
The tetrahedral nature of carbon was first given by
  • Kekule
  • Le Bell and Vant Hoff
  • Pauling
  • Armstrong and Bayer
Carbon containing molecules present in all life forms includes:
  • Carbon dioxide, carbonates and hydrogen carbonates
  • Nucleic acids, carbon dioxied, carbonates and hydrogen carbonates
  • Proteins, carbohydrates, fats, nucleic acids and vitamins
  • Hormones, carbohydrates, Carbonates and hydrogen carbonates
In nature, carbon is found in elemental forms as:
  • Carbon dioxide and carbonates
  • Diamond and graphite
  • Hydrogen carbonates and graphite
  • Carbon dioxide and graphite
The correct statement is :
1817442_0623e8524af34c0f98eb25592fc2f731.jpg
  • $$+5$$ oxidation state of H is more stable than its $$+3$$ oxidation state.
  • $$G^{2+}$$ is the better oxidizing agent than $$G^{4+}$$.
  • $$+3$$ oxidation state of H is more stable than its $$+5$$ oxidation state.
  • The ionization energy of G is greater than that of Tin.
Which of the following compound is most acidic?
  • $$Cl_2O_7$$
  • $$P_4O_{10}$$
  • $$SO_3$$
  • $$B_2O_3$$
Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, carbon attains the electronic configuration of 
  • helium
  • neon
  • argon
  • krypton
Select correct statement(s) :
  • Thermodynamic stability of graphite > diamond, but reverse order is true for their kinetic stability
  • Melting point of $$NaCI > LiCI$$, but reverse order is true for their thermal stability
  • Ionisation energy of $$N_2 > O_2$$, but reverse order of ionisation energy is true for their corresponding atoms
  • Lewis acidic strength of $$Bel_2 > BeF_2$$ , but reverse order is true for their melting point
If P to T are second period p-block elements then which of the following graph show correct relation between valence electrons in $$P_2$$ to $$T_2$$ (corresponding molecules) and their bond order is : 
Which of the following statement is incorrect?
1817443_5125d46e1db549d4bbd192980e728a34.jpg
  • $$B_2C_5$$ is acidic in nature
  • $$AC_2$$ is acidic in nature
  • $$FC_3$$ is basic in nature
  • $$GC_2$$ is amphoteric in nature
The oxidation number of carbon in diamond is:
  • $$zero$$
  • $$+4$$
  • $$-4$$
  • $$+2$$
The nature of aqueous solution of borax is :
  • Acidic
  • Neutral
  • Amphoteric
  • Basic
In which of the following elements +3 oxidation state is most stable?
  • In
  • Ga
  • Al
  • TI
Which of the following is an organo silicon polymer ?
  • Silica
  • Silicone
  • Silicone carbide
  • Silicic acid
$$SiCl_{4} \overset{H_2O}{\longrightarrow} X \overset{Heat}{\longrightarrow} Y \overset{NaOH}{\longrightarrow} Z$$
X, Y and Z in the above reaction are
  • $$X \rightarrow SiO_2 , Y \rightarrow Si , Z \rightarrow NaSi$$
  • $$X \rightarrow Si(OH)_4, Y \rightarrow SiO_2, Z \rightarrow Na_2SiO_3$$
  • $$X \rightarrow Si(OH)_4, Y \rightarrow Si, Z \rightarrow SiO_2$$
  • $$X \rightarrow SiO_2, Y \rightarrow SiCl_{4}, Z \rightarrow Na_2SiO_3$$
Group $$13$$ elements show
  • only $$+1$$ oxidation state
  • only $$+3$$ oxidation state
  • $$+1$$ and $$+3$$ oxidation states
  • $$+1, +2$$ and $$+3$$ oxidation states.
Carborumdum is a:
  • molecular solid
  • covalent solid
  • ionic solid
  • amorphous solid
Which substance is having molecular solid :
  • graphite
  • $$C_{60}$$
  • gold
  • $$Ca_{3}(PO_{4})_{2}$$
Choose the correct order of $$C - C$$ bond length in the given compounds:
  • Acetylene < ethylene < graphite < benzene < ethane
  • Acetylene < ethylene < benzene < graphite < ethane
  • Acetylene < graphite < ethylene < benzene < ethane
  • Acetylene < benzene < graphite < ethylene < ethane
The incorrect stability order of $$+3$$ and $$+1$$ states of $$13th$$ group elements (boron family) is:
  • $$Ga^{3+} < In^{3+} < Tl^{3+}$$
  • $$Tl^{+} > Tl^{3+}$$
  • $$Ga^{+} < ln^{+} < Tl^{+}$$
  • $$Ga^{3+} > Ga^{+}$$
Correct order of bond angle in given species is:
  • $$SiO_{4}^{4-} > PCl_{3} > NCl_{3} > SbH_{3} > H_{2}Te$$
  • $$SiO_{4}^{4-} > NCl_{3} > PCl_{3} > SbH_{3} > H_{2}Te$$
  • $$SiO_{4}^{4-} > H_{2}Te > SbH_{3} > PCl_{3} > NCl_{3}$$
  • $$NCl_{3} > PCl_{3} > SiO_{4}^{4-} > SbH_{3} > H_{2}Te$$
Which is the hardest compound of boron ?
  • $$B_{2}O_{3}$$
  • $$BN$$
  • $$B_{4}C$$
  • $$B_{2}H_{6}$$
Which is not true about borax ?
  • It is a useful primary standard for titrating against acids
  • One mole of borax contains $$4B - O - B$$ bonds
  • Aqueous solution of borax can be used as buffer
  • It is made up of two triangular $$BO_{3}$$ units and two tetrahedral $$BO_{4}$$ units
Which of the following order is incorrect ?
  • Lewis basic character : $$NH_{3} > PH_{3} > AsH_{3} > SbH_{3}$$
  • Bond dissociation energy : $$HF > HCl > HB r > HI$$
  • Thermal stability : $$H_{2}O > H_{2}S > H_{2}Se > H_{2}Te$$
  • Bond angle : $$CH_{4} > SiH_{4} > GH_{4} > SnH_{4}$$
$$SiO_{2}$$ reacts with :
  • $$Na_{2}CO_{3}$$
  • $$CO_{2}$$
  • $$HF$$
  • $$HCl$$
List -I                                              List -2
A. IVA group                                 Crystalline form
B. Onyx                                         2 Amorphous form of silica
C. Lubricant                                  Graphite
D. Hardest material                       4.ns2 np2
Diamond
The correct match with A B C D is ?
  • 2 4 3 5
  • 2 3 5 4
  • 4 2 3 5
  • 5 3 2 4
An alkyl halide reacts with a group 14 element $$Y$$ at 570K with $$Cu$$ as a catalyst and produces a dialkyl chloro compound $$Z$$. The compound $$Z$$ on hydrolysis gives another compound which is a strong water repellent and quite inert chemically. The dioxide of $$Y$$ is acidic in nature. The alkyl halide can also be obtained from methane after monosubstitution. Identify $$Y$$ and $$Z$$.
  • $$Y = Si$$ and $$Z = (CH _{3})_{2} SiCl_{2}$$
  • $$Y = Si$$ and $$Z = CH_{3}Cl$$
  • $$Y = C$$ and $$Z = SiCl_{4} $$
  • $$Y = Si$$ and $$Z = CCl_{4} $$
A metal $$X$$ produces an oxide and nitride on burning in air, but does not liberate hydrogen with alkali. Another metal $$Y$$ produces an oxide and nitride on burning in air and also liberates hydrogen with alkalies. The metals $$X$$ and $$Y$$ respectively are:
  • Na, Mg
  • Mg, Al
  • Na, Al
  • Al, Mg
The substance 'B' is
  • $$Na_2B_{4}O_{7}$$
  • $$B_{2}O_{3}$$
  • $$H_{3}BO_{3}$$
  • $$HBO_{2}$$
Match the ores from List-I with their corresponding formulae from List-II.

List -I                                                        List -II
A. Borax                                                   1) $$Al_{2}O_{3}.2H_{2}O$$
B. Razorite                                               2) $$Ca_{2}B_{6}O_{11}.5H_{2}O$$ 
C. Bauxite                                                3) $$Na_{2}B_{4}O_{7}.4H_{2}O$$
D.Colemanite                                           4) $$Na_{2}B_{4}O_{7}.10H_{2}O$$
  • A-3, B-4, C-2, D-1
  • A-2, B-3, C-4, D-1
  • A-4, B-3, C-1, D-2
  • A-1, B-2, C-3, D-4
The number of $$-OH$$ units directly bonded to boron atoms in borax is:
  • 10
  • 4
  • 5
  • 3
The tendency to show inert pair effect follows the order :
  • $$Ga< Al< In< Tl< B$$
  • $$B< Al< Ga< In< Tl$$
  • $$B=Al=Ga< In< Tl$$
  • $$Tl< In< Ga< Al< B$$
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