Q.1 Which of the following elements belongs to Group 13?
Carbon
Boron
Nitrogen
Oxygen
Explanation - Boron is the first element of Group 13 (also called the Boron group).
Correct answer is: Boron
Q.2 The oxidation state of thallium in Tl2O3 is:
+1
+2
+3
+5
Explanation - In Tl2O3, each thallium atom has an oxidation state of +3 because 2*(+3) + 3*(-2) = 0.
Correct answer is: +3
Q.3 Which of the following is the most reactive element in Group 14?
Carbon
Silicon
Tin
Lead
Explanation - Carbon forms multiple bonds and reacts more readily than heavier Group 14 elements due to higher electronegativity and smaller size.
Correct answer is: Carbon
Q.4 Which oxide of boron is acidic in nature?
B2O3
B2O2
B2O
B2O4
Explanation - Boron trioxide (B2O3) reacts with water to form boric acid (H3BO3), making it acidic.
Correct answer is: B2O3
Q.5 The inert pair effect is most prominently observed in which element of Group 13?
Boron
Aluminium
Gallium
Thallium
Explanation - Thallium shows the +1 oxidation state due to inert pair effect, which increases down the group.
Correct answer is: Thallium
Q.6 Which of the following has a diamond cubic structure?
Carbon
Silicon
Germanium
All of the above
Explanation - Carbon (diamond), Silicon, and Germanium all crystallize in a diamond cubic structure.
Correct answer is: All of the above
Q.7 Which hydride of Group 14 element is the most acidic?
CH4
SiH4
GeH4
SnH4
Explanation - Acidity increases down the group, making stannane (SnH4) the most acidic among these hydrides.
Correct answer is: SnH4
Q.8 Which of the following elements forms a stable +3 oxidation state in its compounds?
Boron
Aluminium
Gallium
All of the above
Explanation - All Group 13 elements can show +3 oxidation state; however, the stability varies down the group.
Correct answer is: All of the above
Q.9 Which of the following is a metalloid in Group 13?
Boron
Aluminium
Gallium
Indium
Explanation - Boron shows properties of both metals and non-metals, classifying it as a metalloid.
Correct answer is: Boron
Q.10 Lead predominantly shows which oxidation state?
+2
+4
+3
-2
Explanation - Lead predominantly shows +2 oxidation state due to inert pair effect making the +4 state less stable.
Correct answer is: +2
Q.11 Which Group 14 element forms the strongest C–C bond?
Carbon
Silicon
Germanium
Tin
Explanation - Carbon forms very strong C–C bonds due to its small size and ability to form multiple bonds.
Correct answer is: Carbon
Q.12 Which element of Group 13 is a liquid at room temperature?
Boron
Aluminium
Gallium
Thallium
Explanation - Gallium has a melting point slightly above room temperature (29.7°C), so it can melt in hand.
Correct answer is: Gallium
Q.13 Which of the following is amphoteric?
Al2O3
B2O3
Ga2O3
In2O3
Explanation - Aluminium oxide reacts with both acids and bases, showing amphoteric behavior.
Correct answer is: Al2O3
Q.14 Which of the following is used in making semiconductors?
Carbon
Silicon
Tin
Lead
Explanation - Silicon is widely used in semiconductors due to its ability to conduct under certain conditions.
Correct answer is: Silicon
Q.15 Which Group 14 element reacts with Cl2 to form a tetrachloride at room temperature?
Carbon
Silicon
Lead
Tin
Explanation - Carbon reacts with chlorine to form CCl4 (carbon tetrachloride) under normal conditions.
Correct answer is: Carbon
Q.16 Which is a poisonous oxide of lead?
PbO
PbO2
Pb3O4
All of the above
Explanation - All lead oxides are toxic and can cause lead poisoning if ingested or inhaled.
Correct answer is: All of the above
Q.17 Which element forms a hydride that is polymeric in nature?
Boron
Aluminium
Gallium
Indium
Explanation - Boron forms BH3 which dimerizes to B2H6, a polymeric hydride.
Correct answer is: Boron
Q.18 Which element of Group 13 exhibits diagonal relationship with silicon?
Boron
Aluminium
Gallium
Indium
Explanation - Boron shows a diagonal relationship with silicon, displaying similarities in size and chemical behavior.
Correct answer is: Boron
Q.19 Which of the following elements does not form multiple bonds easily?
Carbon
Silicon
Germanium
Tin
Explanation - Heavier Group 14 elements like tin have larger atomic size, preventing efficient pi-bond formation.
Correct answer is: Tin
Q.20 Which element forms the least stable hydride?
CH4
SiH4
GeH4
SnH4
Explanation - Stannane (SnH4) is less stable due to weaker Sn–H bonds and larger atomic size.
Correct answer is: SnH4
Q.21 Which oxide of Group 14 element shows acidic nature?
CO2
SiO2
GeO2
SnO2
Explanation - CO2 reacts with water to form carbonic acid, showing acidic behavior.
Correct answer is: CO2
Q.22 Which Group 13 element is used in thermometers due to low melting point?
Boron
Aluminium
Gallium
Thallium
Explanation - Gallium melts slightly above room temperature, making it suitable for thermometers and heat sensors.
Correct answer is: Gallium
Q.23 Which element of Group 14 is used in nuclear reactors?
Carbon
Silicon
Lead
Tin
Explanation - Lead is used as a coolant and shielding material in nuclear reactors due to high density and low neutron absorption.
Correct answer is: Lead
Q.24 Which of the following Group 13 oxides is covalent in nature?
B2O3
Al2O3
Ga2O3
Tl2O3
Explanation - Boron trioxide (B2O3) is covalent, whereas other oxides in the group are largely ionic.
Correct answer is: B2O3
Q.25 Which hydride of Group 14 is tetrahedral in geometry?
CH4
SiH4
GeH4
All of the above
Explanation - All hydrides of Group 14 elements are tetrahedral due to sp3 hybridization.
Correct answer is: All of the above