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SAMPLE PAPER (2025-26)
CHEMISTRY THEORY (043)
M ax. M arks:70 Time: 3 hours
General Instructions:
Read the following instructions carefully.
(a) There are 33 questions in this question paper with internal choice.
(b) SECTION A consists of 16 multiple -choice questions carrying 1 mark each.
(c) SECTION B consists of 5 short answer questions carrying 2 marks each.
(d) SECTION C consists of 7 short answer questions carrying 3 marks each.
(e) SECTION D consists of 2 case - based questions carrying 4 marks each.
(f) SECTION E consists of 3 long answer questions carrying 5 marks each.
(g) All questions are compulsory.
(h) Use of log tables and calculators is not allowed.
SECTION A
The following questions are multiple -choice questions with one correct answer. Each question carries 1
mark. There is no internal choice in this section.
- Which of the following solutions will have the highest conductivity at 298 K?
(a) 0.01 M HCl solution (b) 0.1 M HCl solution
(c) 0.01 M CH 3
COOH solution (d) 0.1 M CH 3
COOH
solution
Identify A and B:
(a) A = 1-phenylethanal , B = acetophenone (b) A = Benzophenone B = formaldehyde
(c) A= Benzaldehyde , B = Acetophenone (d) A = Benzophenone , B = Acetophenone
- The vitamins which can be stored in our body are:
(a) Vitamin A, B, D and E (d) Vitamin A, C, D and K
(c) Vitamin A, B, C and D (d) Vitamin A, D, E and K
What is IUPAC name of the ketone A, which undergoes iodoform reaction to
give
CH
3
CH= C(CH
3
)COONa and yellow precipitate of CHI 3
(a) 3-Methylpent-3-en-2one (b) 3-Methylbut-2-en- one
(c) 2, 3-Dimethylethanone (d) 3-Methylpent-4-one
- Which of the following is not correct?
(a) In haloarenes, the electron pairs on halogen atom are in conjugation with π-electrons of
the ring.
(b) The carbon-magnesium bond is covalent and non-polar in nature.
(c)
During S N
1
reaction, the carbocation formed in the slow step being sp2 hybridised is planar.
(d)
Out of CH 2
= CH-Cl and C 6
H
5
CH
2
Cl, C 6
H
5
CH
2
Cl is more reactive towards S N
1
reaction
- Match the properties with the elements of 3d series:
(i) lowest enthalpy of atomisation (p) Sc
(ii) shows maximum number of oxidation states (q) Mn
(iii) transition metal that does not form coloured compounds (r) Zn
(s) Ti
(a) (i) (r), (ii) (q), (iii) (p) (b) (i) (r), (ii) (s), (iii) (p)
(c) (i) (p), (ii) (q), (iii) (r) (d) (i) (s), (ii) (r), (iii) (p)
- Which of the following statement is true?
(a) molecularity of reaction can be zero or a fraction.
(b) molecularity has no meaning for complex reactions.
(c) molecularity of a reaction is an experimental quantity
(d) reactions with the molecularity three are very rare but are fast.
In which of the following solvents, the C 4
H
8
NH
3
X– is soluble;
(a) ether (b) acetone (c) water (d) bromine water
- Which of the following observation is shown by 2 -phenyl ethanol with Lucas Reagent?
(a) Turbidity will be observed within five minutes
(b) No turbidity will be observed
(c) Turbidity will be observed immediately
(d) Turbidity will be observed at room temperature but will disappear after five minutes.
- If the initial concentration of substance A is 1.5 M and after 120 seconds the
concentration
of substance A is 0.75 M, the rate constant for the reaction if it follows zero - order kinetics is:
(a)
molL
s
(b) 0.00625 s
(c) 0.00578 molL
s
(d) 0.00578 s
- Anisole undergoes bromination with bromine in ethanoic acid even in the absence of iron
(III) bromide catalyst
(a) Due to the activation of benzene ring by the methoxy group.
(b) Due to the de-activation of benzene ring by the methoxy group.
(c) Due to the increase in electron density at ortho and para positions
(d) Due to the formation of stable carbocation.
- The trend of which property is represented by the following graph?
(a) ionization enthalpy (b) atomic radii
(c) enthalpy of atomization (d) melting point
SECTION B
This section contains 5 questions with internal choice in one question. The following questions are
very short answer type and carry 2 marks each.
- a. Radioactive decay follows first - order kinetics. The initial amount of two radioactive
elements X and Y is 1 gm each. What will be the ratio of X and Y after two days if their
half- lives are 12 hours and 16 hours respectively?
b. The hypothetical reaction P + Q R is half order w.r.t ‘P’ and zero order w.r.t ‘Q’.
What is the unit of rate constant for this reaction?
A 5% solution of Na 2
SO
4
.10H
2
O (MW = 3 22) is isotonic with 2% solution of non- electrolytic,
non
volatile substance X. Find out the molecular weight of X.
- (a) Arrange the isomeric dichlorobenzene in the increasing order of their boiling point and
melting points.
(b) Explain why the electrophilic substitution reactions in haloarenes occur slowly and
require more drastic conditions as compared to those in benzene.
- (a) Out of p-tolualdehyde and p-nitrobenzaldehyde, which one is more reactive towards
nucleophilic addition reactions, why?
(b) Write the structure of the product formed when acetone reacts with 2,4 DNP reagent.
OR
Convert the following:
(a) Benzene to m-nitrobenzaldehyde
(b) Bromobenzene to benzoic acid
- (a) DNA fingerprinting is used to determine paternity of an individual. Which property of
DNA helps in the procedure?
(b) What structural change will occur when a native protein is subjected to change in pH?
SECTION C
This section contains 7 questions with internal choice in one question. The following questions are
short answer type and carry 3 marks each.
- (a) Write the formula for the following coordination
compound Bis(ethane-1,2-diamine)
dihydroxidochromium(III) chloride
(b)
Does ionization isomer for the following compound exist? Justify your answer.
Hg[Co(SCN) 4
]
(c) Is the central metal atom in coordination complexes a Lewis acid or a Lewis base? Explain.
(a) Can we construct an electrochemical cell with two half-cells composed of ZnSO 4
solution
and zinc electrodes? Explain your answer.
(b)
Calculate the λ
0
m
for Cl- ion from the data given below:
0
m MgCl 2 = 258.6 Scm2mol–1 and λ
0
m Mg2+ = 106 Scm2mol–
(c)
The cell constant of a conductivity cell is 0.146 cm
- . What is the conductivity of 0.01 M
solution of an electrolyte at 298 K, if the resistance of the cell is 1000 ohm?
- Write the name of the reaction, structure and IUPAC name of the product formed when (any 2) :
(a)
phenol reacts with CHCl 3
in the presence of NaOH followed by hydrolysis.
(b)
CH
3
CH
2
CH(CH
3
)CH(CH
3
)ONa reacts with C 2
H
5
Br
(c)
CH
3
CH
2
CN reacts with stannous chloride in the presence of hydrochloric acid followed
by hydrolysis
- You are given four organic compounds “A”, “B”, “C” and “D”. The compounds “A”, “B” and
“C” form an orange- red precipitate with 2,4 DNP reagent. Compounds “A” and “B” reduce
Tollen’s reagent while compounds “C” and “D” do not. Both “B” and “C” give a yellow
precipitate when heated with iodine in the presence of NaOH. Compound “D” gives brisk
effervescence with sodium bicarbonate solution. Identify “A”, “B”, “C” and “D” given the
number of carbon atoms in three of these carbon compounds is three while one has two
carbon atoms. Give an explanation for y our answer.
- When sucrose is hydrolysed the optical rotation values are measured using a polarimeter
and are given in the following table:
S.No. Time (hours) Specific Rotation
66.5o
o
(a) Account for the two specific rotation values.
(b) What is the specific name given to sucrose based on the above observation?
(c) One of the products formed during the hydrolysis of sucrose is a glucose, that reacts
with hydroxylamine to give compound A. Identify compound A.
An organic compound A with the molecular formula (+)C 4
H
9
Br undergoes hydrolysis to
form (+) C 4 H 9 OH. Give the structure of A and write the mechanism of the reaction.
The rate constants of a reaction at 200K and 500K are 0.02s
and 0.20s
respectively. Calculate
the value of Ea (Given 2.303R = 19.15 JK
mol
SECTION D
The following questions are case -based questions. Each question has an internal choice and
carries 4 (1+1+2) marks each. Read the passage carefully and answer the questions that follow.
- Crystal field splitting by various ligands
Metal complexes show different colours due to d-d transitions. The complex absorbs light of specific
wavelength to promote the electron from t2g to eg level. The colour of the complex is due
to the transmitted light, which is complementary of the colour absorbed.
The wave number of light absorbed by different complexes of Cr ion are given below:
Complex Wavenumber of light absorbed (cm-1) Energy of light absorbed(kJ/mol)
[CrA 6 ]3- 13640 163
[CrB 6 ]3+ 17830 213
[CrC
6
]3+
[CrD 6
]3-
Imagine you are a member of an agency funding scientific research. Which of the
following projects will you fund and why?
(i) safe recycling of lead batteries
(ii) extraction of hydrogen
SECTION E
The following questions are long answer type and carry 5 marks each. All questions have an
internal choice.
- Attempt any five of the following:
(a) Which of the following ions will have a magnetic moment value of 1.
BM. Sc
3+
, Ti
3+
, Ti
2+
, Cu
2+
, Zn
2+
(b) In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode,
Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -
0.76 V respectively.)
(c) The second ionization enthalpies of chromium and manganese are 1592 and 1509
kJ/mol respectively. Explain the lower value of Mn.
(d) Give two similarities in the properties of Sc and Zn.
(e) What is actinoid contraction? What causes actinoid contraction?
(f) What is the oxidation state of chromium in chromate ion and dichromate ion?
(g)
Write the ionic equation for reaction of KI with acidified KMnO 4
- (a) What is the effect of temperature on the solubility of glucose in water?
(b) Ibrahim collected a 10mL each of fresh water and ocean water. He observed that one
sample labeled “P” froze at 0
o
C while the other “Q” at -1.
o
C. Ibrahim forgot which of the
two, “P” or “Q” was ocean water. Help him identify which container contains ocean
water, giving rationalization for your answer.
(c)
Calculate Van't Hoff factor for an aqueous solution of K 3
[Fe(CN) 6
] if the degree of
dissociation
(α) is 0.852. What will be boiling point of this solution if its concentration is 1
molal? (Kb=0.52 K kg/mol)
OR
(a) What type of deviation from Roult’s Law is expected when phenol and aniline are
mixed with each other? What change in the net volume of the mixture is expected?
Graphically represent the deviation.
(b) The vapour pressure of pure water at a certain temperature is 23.80 mm Hg. If 1 mole of a
non- volatile non- electrolytic solute is dissolved in 100g water, Calculate the resultant vapour
pressure of the solution.
An organic compound with molecular formula C 7
H
7
NO
2
exists in three isomeric forms, the
isomer ‘A’ has the highest melting point of the three. ‘A’ on reduction gives compound ‘B’
with molecular formula C 7 H 9 N. ‘B’ on treatment with NaNO 2 /HCl at 0-5 0C to form
compound ‘C’. On treating C with H 3 PO 2 ,it gets converted to D with formula C 7 H 8 , which
on further reaction with CrO 2 Cl 2 followed by hydrolysis forms ‘E’ C 7 H 6 O. Write the
structure of compounds A to E. Write the chemical equations involved.
OR
(a) Account for the following:
(i) N-ethylbenzenesulphonyl amide is soluble in alkali.
(ii) Reduction of nitrobenzene using Fe and HCl is preferred over Sn and HCl.
(b) Arrange the following in:
(i)
decreasing order of pK b
values
C 6 H 5 NH 2 , C 6 H 5 NHCH 3 , C 6 H 5 CH 2 NH 2 , CH 3 NH 2 , NH 3
(ii) increasing order of solubility in
water
C
2
H
5
Cl, C 2
H
5
NH
2
, C
2
H
5
OH
(iii) decreasing boiling point
CH
3
COOH, C
2
H
5
OH, CH
3
NH
2
, CH
3
OCH
3
