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Free download in PDF CBSE Class 12 Chemistry Objective Type Questions with Answers. Here Gkseries provide Chemistry Solve Questions and Answers for CBSE Class 12 Students.
121
Which one of the following metals is required as cofactor by all enzymes utilizing ATP in phosphate transfer?
[A]
Mg
[B]
He
[C]
K
[D]
Ca
122
Which of the following polymer is stored in the liver of animals?
[A]
Glycogen
[B]
Amylopectin
[C]
Amylose
[D]
Cellulose
Answer: slope of velocity-time graph
123
Which of the following acids is a vitamin?
[A]
Ascorbic acid
[B]
Adipic acid
[C]
Aspartic acid
[D]
Saccharic acid
124
Each polypeptide in a protein has aminoacids linked with each other in a specific sequence. This sequence of amino acids is said to be __________ .
[A]
primary structure of proteins.
[B]
secondary structure of proteins.
[C]
tertiary structure of proteins.
[D]
quaternary structure of proteins.
Answer: primary structure of proteins.
125
Which of the following reactions of glucose can be explained only by its cyclic structure? [NCERT Exemplar]
[A]
Pentaacetate of glucose does not react with hydroxylamine.
[B]
Glucose is oxidised by nitric acid to gluconic acid.
[C]
Glucose forms pentaacetate.
[D]
Glucose reacts with hydroxylamine to form an oxime.
Answer: Pentaacetate of glucose does not react with hydroxylamine.
126
The sugar present in milk is
[A]
lactose
[B]
Glucose
[C]
Sucrose
[D]
Maltose
127
Which of the following has magnesium?
[A]
Vitamin B12
[B]
Chlorophll
[C]
Haemocyanin
[D]
Carbonic anhydrate
128
Trunbull’s blue is
[A]
Ferrous ferricyanide
[B]
Fe3[Fe(CN)6]4
[C]
Ferrous cyanide
[D]
Ferricyanide
Answer: Ferrous ferricyanide
129
Among the ligands NH3, en, CN and CO, the correct order of field strength is
[A]
NH3 < en < CN– < CO
[B]
CN– < NH3 < CO < en
[C]
en < CN–< NH3 < CO
[D]
CO < NH3 < en < CN–
Answer: NH3 < en < CN– < CO
130
Transistion metals, despite high E° oxidation, are poor reducing agents. The incorrect reason is
[A]
complex forming nature.
[B]
low heats of hydration.
[C]
high ionization energies.
[D]
high heat of vaporization.
Answer: complex forming nature.
131
Which of the following is incorrect for KMnO4 to be used as an oxidising agent?
[A]
The number of electrons involved in oxidation of KMnO4 in acidic medium is 3.
[B]
The equivalent weight of KMnO4 in basic medium is 158.
[C]
Nitric acid is not used for the above purpose because it itself acts as a self oxidising agent and will react with the reducing agent.
[D]
HCl cannot be used because some KMnO4 is consumed in the reaction.
Answer: The number of electrons involved in oxidation of KMnO4 in acidic medium is 3.
132
The property which is not characteristic of transistion metals is
[A]
natural radioactivity.
[B]
formation of coloured compounds.
[C]
tendency to form complexes.
[D]
variable oxidation states.
Answer: natural radioactivity.
133
Which one of the following characteristics of the transistion metals is associated with higher catalytic activity?
[A]
Colour of hydrate ions
[B]
Variable oxidation states
[C]
Paramagnetic behaviour
[D]
High enthalpy of atomisation
Answer: Variable oxidation states
134
Which of the following are d-block elements but not regarded as transistion elements?
[A]
Zn, Cd, Hg
[B]
Ru, Rh, Pd
[C]
Fe, Co, Ni
[D]
Cu, Ag, Au
135
Anomalous electronic configuration in the 3d series are of
[A]
Cr and Cu
[B]
Fe and Cu
[C]
Cr and Fe
[D]
Cu and Zn
136
The increasing order of reducing power of the halogen acids is
[A]
HF < HCl < HBr < HI
[B]
HCl < HBr < HF < HI
[C]
HI < HBr < HCl < HF
[D]
HBr < HCl < HF < HI
Answer: HF < HCl < HBr < HI
137
Helium is preferred to be used in balloons instead of hydrogen because it is
[A]
incombustible
[B]
non polarizable
[C]
lighter than hydrogen
[D]
more abundant than hydrogen
138
H2S is more acidic than H2O because
[A]
oxygen is more electronegative than sulphur.
[B]
atomic number of sulphur is higher than oxygen.
[C]
H — S bond dissociation energy is less as compared to H — O bond.
[D]
H — O bond dissociation energy is less also compared to H — S bond.
Answer: atomic number of sulphur is higher than oxygen.
139
When Cl2 reacts with hot and cone. NaOH, the oxidation number of chlorine changes from
[A]
zero to +1 and zero to +5
[B]
0 to -1 and 0 to +5
[C]
zero to -1 and zero to +3
[D]
0 to +1 and 0 to -3
Answer: 0 to -1 and 0 to +5
140
Fluorine differs from rest of the halogens in some of its properties. This is due to
[A]
its smaller size and high electronegativity.
[B]
lack of d-orbitals.
[C]
low bond dissociation energy.
[D]
All of the these.
Answer: lack of d-orbitals.
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