CBSE Class 11 Chemistry Hydrogen MCQs Set B

Question: Permanent hardness of water can be removed by adding Calgon (NaPO₃)n. This is an example of
a) Adsorption
b) Exchange of ion
c) Precipitation
d) None of the options
Answer: b

Question: Which of the following is not a use of dihydrogen ?
a) It used in fuel cells for generating electrical energy.
b) Atomic hydrogen and oxy-hydrogen torches are used for cutting and welding purposes.
c) It used in the synthesis of hydroquinone and tartaric acid.
d) Both Atomic hydrogen and oxy-hydrogen torches are used for cutting and welding purposes. and It used in the synthesis of hydroquinone and tartaric acid.
Answer: c

Question: Which of the following statements do not define the characteristic property of water “Water is a universal solvent”
a) It can dissolve maximum number of compounds
b) It has very low dielectric constant
c) It has high liquid range
d) None of the options
Answer: b

Question: Hydrogen is not obtained when zinc reacts with
a) Cold water
b) dil. HCl
c) dil. H₂SO₄
d) Hot NaOH (20%)
Answer: a

Question: Hydrogen molecules differs from chlorine molecule in the following respect
a) Hydrogen molecule is non-polar but chlorine molecule is polar
b) Hydrogen molecule is polar while chlorine molecule is non-polar
c) Hydrogen molecule can form intermolecular hydrogen bonds but chlorine molecule does not
d) Hydrogen molecule cannot participate in coordination bond formation but chlorine molecule can
Answer: d

Question: Permanent hardness of water is due to the presence of
a) bicarbonates of sodium and potassium
b) chlorides and sulphates of sodium and potassium
c) chlorides and sulphates of calcium and magnesium
d) bicarbonates of calcium and magnesium
Answer: c

Question: Which of the following statements is incorrect?
a) Ionic hydrides are stoichiometric compounds of dihydrogen formed with most of s-block elements
b) Ionic hydrides are crystalline, non-volatile and nonconducting in solid state.
c) Melts of ionic hydrides conduct electricity and liberate dihydrogen gas at cathode.
d) Both Ionic hydrides are stoichiometric compounds of dihydrogen formed with most of s-block elements and Melts of ionic hydrides conduct electricity and liberate dihydrogen gas at cathode.
Answer: c

Question: Which of the following metals reacts with H2O at room temp?
a) Ag
b) Fe
c) Al
d) Na
Answer: d

Question: In Bosch’s process which gas is utilised for the production of hydrogen gas ?
a) Producer gas
b) Water gas
c) Coal gas
d) None of the options
Answer: b

Question: Which of the following groups of ions makes the water hard?
a) Sodium and bicarbonate
b) Magnesium and chloride
c) Potassium and sulphate
d) Ammonium and chloride.
Answer: b

Question: The boiling point of water is exceptionally high because
a) there is covalent bond between H and O
b) water molecule is linear
c) water molecules associate due to hydrogen bonding
d) water molecule is not linear
Answer: c

Question: Which of the following metal evolves hydrogen on reacting with cold dilute HNO₃ ?
a) Mg
b) Al
c) Fe
d) Cu
Answer: a

Question: Which one of the following pairs of substances on reaction will not evolve H₂ gas?
a) Iron and H₂SO₄ (aqueous)
b) Iron and steam
c) Copper and HCl (aqueous)
d) Sodium and ethyl alcohol
Answer: c

Question: Water is :
a) more polar than H₂S
b) more or less identical in polarity with H₂S
c) less polar than H₂S
d) None of the options
Answer: a

Question: The unusual properties of water in the condensed phase (liquid and solid states) are due to the
a) presence of hydrogen and covalent bonding between the water molecules
b) presence of covalent bonding between the water molecules
c) presence of extensive hydrogen bonding between water molecules
d) presence of ionic bonding
Answer: c

Question: Very pure hydrogen (99.9) can be made by which of the following processes ?
a) Reaction of methane with steam
b) Mixing natural hydrocarbons of high molecular weight
c) Electrolysis of water
d) Reaction of salts like hydrides with water
Answer: d

Question: Hydrogen bond energy is equal to :
a) 3-7 cals
b) 30-70 cals
c) 3-10 kcals
d) 30-70 kcals
Answer: c

Question: Water possesses a high dielectric constant, therefore :
a) it always contains ions
b) it is a universal solvent
c) can dissolve covalent compounds
d) can conduct electricity
Answer: b

Question: Choose the correct option for following hydrides. B₂H₆, CH₄, NH₃ and HF
a) Electron deficient hydride = B₂H₆ and HF Electron precise hydride = CH₄ Electron rich hydride = NH₃
b) Electron deficient hydride = B₂H₆ Electron precise hydride = CH4 Electron rich hydride = NH₃ and HF
c) Electron deficient hydride = CH₄ Electron precise hydride = B₂H₆ Electron rich hydride = NH₃ and HF
d) Electron deficient hydride = CH₄ and HF Electron precise = B₂H₆ Electron rich hydride = NH₃,
Answer: b

Question: The low density of ice compared to water is due to
a) hydrogen-bonding interactions
b) dipole-dipole interactions
c) dipole-induced dipole interactions
d) induced dipole-induced dipole interactions
Answer: a

Question: Hydrogen can behave as a metal
a) at very high temperature
b) at very low temperature
c) at very high pressure
d) at very low pressure
Answer: c

Question: The process used for the removal of hardness of water is
a) Calgon
b) Baeyer
c) Serpeck
d) Hoope
Answer: a

Question: Saline hydrides react explosively with water, such fires can be extinguished by
a) water
b) carbon dioxide
c) sand
d) None of the options
Answer: c

Question: The property of hydrogen which distinguishes it from alkali metals is
a) its electropositive character
b) its affinity for non metal
c) its reducing character
d) its non-metallic character
Answer: d

Question: Which hydride is an ionic hydride ?
a) H₂S
b) TiH1.73
c) NH₃
d) NaH
Answer: d

Question: Hydrogen accepts an electron to form inert gas configuration. In this it resembles
a) halogen
b) alkali metals
c) chalcogens
d) alkaline earth metals
Answer: a

Question: Which of the following statements is correct ?
a) Hydrogen has same IP as alkali metals
b) Hydrogen has same electronegativity as halogens
c) It has oxidation number of –1 and +1
d) It will not be liberated at anode
Answer: c

Question: Why does H⁺ ion always get associated with other atoms or molecules?
a) Ionisation enthalpy of hydrogen resembles that of alkali metals.
b) Its reactivity is similar to halogens.
c) It resembles both alkali metals and halogens.
d) Loss of an electron from hydrogen atom results in a nucleus of very small size as compared to other atoms or ions. Due to small size it cannot exist free.
Answer: d

Question: Which of the following is formed on reaction of carbon monoxide gas with dihydrogen in presence of cobalt as a catalyst?
a) Methanal
b) Methanol
c) Methane
d) Formic acid
Answer: b

Question: The polymeric hydride is
a) CaH₂
b) NaH
c) BaH₂
d) MgH₂
Answer: d

Question: Elements of which of the following group(s) of periodic table do not form hydrides.
a) Groups 7, 8, 9
b) Group 13
c) Groups 15, 16, 17
d) Group 14
Answer: a

Question: Ionic hydrides reacts with water to give
a) acidic solutions
b) hydride ions
c) basic solutions
d) electorns
Answer: c

Question: Which of the following is formed when zinc reacts with sodium hydroxide?
a) Hydrogen gas
b) Sodium zincate
c) Zinc oxide
d) Both Hydrogen gas and Sodium zincate
Answer: d

Question: When two ice cubes are pressed over each other, they uniteto form one cube. Which of the following forces is responsible to hold them together ?
a) Hydrogen bond formation
b) Van der Waals forces
c) Covalent attraction
d) Ionic interaction
Answer: a

Question: LiAlH4 is used as :
a) An oxidizing agent
b) A reducing agent
c) A mordant
d) A water softener
Answer: b

Question: Number of neutrons in three isotopes of hydrogen, protium, deuterium and tritium respectively is
a) 0, 1, 2
b) 1, 1,1
c) 2, 1, 0
d) 2, 0, 1
Answer: a

Question: Which one the following removes temporary hardness of water ?
a) Slaked lime
b) Plaster of Paris
c) Epsom
d) Hydrolith
Answer: a

Question: Elements of which of the following group do not form hydrides?
a) Alkali metals
b) Halogens
c) Alkaline earth metals
d) Noble gases
Answer: d

Question: At its melting point ice is lighter than water because
a) H₂O molecules are more closely packed in solid state
b) ice crystals have hollow hexagonal arrangement of H₂O molecules.
c) on melting of ice the H₂O molecule shrinks in size
d) ice froms mostly heavy water on first melting.
Answer: b

Question: Hydrogen is evolved by the action of cold dil. HNO₃ on
a) Fe
b) Mn
c) Cu
d) Al
Answer: b

Question: Which one of the following pairs of substances will not produce hydrogen when reacted together?
a) Copper and conc. nitric acid
b) Ethanol and metallic sodium
c) Magnesium and steam
d) Phenol and metallic sodium
Answer: a

Question: Which one of the following is not an isotope of hydrogen ?
a) Deuterium
b) Tritium
c) Ortho hydrogen
d) None of the options
Answer: c

Question: The H–O–H angle in water molecule is about
a) 90º
b) 180º
c) 102.5°
d) 104.5º
Answer: d

Question: Which of the following in incorrect statement?
a) s-block elements, except Be and Mg, form ionic hydride
b) BeH₄, MgH₂, CuH₂, ZnH₂, CaH₂ and HgH₂ are intermediate hydride
c) p-block elements form covalent hydride
d) d-and f-block elements form ionic hydride
Answer: d

Question: Metal hydride on treatment with water gives
a) H₂O₂
b) H₂O
c) Acid
d) Hydrogen
Answer: d

Question: Why is water gas (mixture of CO and H₂) also called ‘syn gas’?
a) Because it is synthesised from sewage, saw – dust, scrap wood etc.
b) Because it is synthesised from methane gas
c) Because it is used in the synthesis of methanol and a number of hydrocarbons.
d) None of the options
Answer: c

Question: Metal hydrides are ionic, covalent or molecular in nature. Among LiH, NaH, KH, RbH, CsH, the correct order of increasing ionic character is
a) LiH > NaH > CsH > KH > RbH
b) LiH < NaH < KH < RbH < CsH
c) RbH > CsH > NaH > KH > LiH
d) NaH > CsH > RbH > LiH > KH
Answer: b

Question: When zeolite (hydrated sodium aluminium silicate) is treated with hard water the sodium ions are exchanged with
a) H⁺ ions
b) Ca²⁺ ions
c) SO₄²⁻ ions
d) OH– ions
Answer: b

Question: Which isotope(s) of hydrogen is/are radioactive and emits low energy β– particles?
(i) Protium (ii) Tritium
(iii) Deuterium
a) (i) and (ii)
b) (iii) only
c) (ii) only
d) (ii) and (iii)
Answer: c

Question: Following are some properties of hydrogen which of the following properties resemble with alkali metals and which with halogens
(i) Hydrogen lose one electron to form unipositive ions
(ii) Hydrogen gain one electron to form uninegative ions
(iii) Hydrogen forms oxides, halides and sulphides
(iv) Hydrogen has a very high ionization enthalpy
(v) Hydrogen forms a diatomic molecule, combines with elements to form hydrides and covalent compounds.
a) Alkali metals resemble (i), (iii) and (iv) Halogens resemble (ii) and (v)
b) Alkali metals resemble (i) and (iii) Halogens resemble (ii), (iii) and (v)
c) Alkali metals resemble (i) and (iii) Halogens resemble (ii), (iv) and (v)
d) Alkali metals resemble (i) only Halogens resemble (iv) and (v)
Answer: c