Sample QuestionsMODEL PAPER 2025 questions
One sample from each question group in this chapter. Select any group above to see the full set with answer keys.
Match the properties given in column $I$ with the metals in column $II$
| Column $I$ |
Column $II$ |
| $(1)$ Actinoid having configuration $(RN)5f^76d^17s^2$ |
$(A) \ Ce$ |
| $(2)$ Lanthanoid which has $4f^{14}$ electronic configuration in $+3$ oxidation state. |
$(B) \ Lu$ |
| $(3)$ Lanthanoid which show $+4$ Oxidation state |
$(C) \ Cm$ |
View full solution →Ammonolysis of ethyl chloride followed by reaction of the amine so formed with 1 mole of methyl chloride gives an amine that
Which of the following compound gives an oxime with hydroxylamine:
Which one of the following has the highest dipole moment?
Assertion $(A)$: For strong electrolytes, there is a slow increase in molar conductivity with dilution and can be represented by the equation
$\Lambda_m^0=\Lambda_m-A c^{1 / 2}$
Reason $(R)$: The value of the constant $'A\ '$ for $\ce{NaCl, CaCl_2},$ and $\ce{MgSO_4}$ in a given solvent and at a given temperature is different.
View full solution →Assertion $(A): \ce{[Mn(CN)_6]}^3- $ has a magnetic moment of two unpaired electrons while $\ce{[MnCl_6]^{3-}}$ has a paramagnetic moment of four unpaired electrons.
Reason $(R): \ce{[Mn(CN)_6]^{3-}}$ is inner orbital complexes involving $\ce{d^2sp^3}$ hybridisation, on the other hand, $\ce{[MnCl_6]^{3-}}$ is outer orbital complexes involving $\ce{sp^{3}d^2}$ hybridisation.
View full solution →Assertion $(A)$: The half $-$ life for a zero order reaction is independent of the initial $1$ concentration of the reactant.
Reason $(R)$: For a zero order reaction, Rate $= k$
View full solution →Assertion $(A)$ : Glucose does not form the hydrogensulphite addition product with $\ce{NaHSO_3}$ .
Reason $(R)$ : Glucose exists in a six $-$ membered cyclic structure called pyranose structure
View full solution →The presence of Carbonyl group in glucose is confirmed by its reaction with hydroxylamine. Identify the type of carbonyl group present and its position. Give a chemical reaction in support of your answer.
Complete the following reactions by writing the major and minor product in each
case $($any $2)$
a. $\ce{CH_3CH_2Br + KCN \rightarrow}$
b.$\ce{CH_3CH_2CH=CH_2 + HBr \rightarrow}$
c. $\ce{(CH_3)_2CHCHCICH_3 + alc KOH \rightarrow}$
View full solution →Observe the following cell and answer the questions that follow:
a. Represent the cell shown in the figure.
b. Name the carriers of the current in the salt bridge
c. Write the reaction taking place at the anode.
a. Write the $\text{IUPAC}$ name of the following complex : $\ce{K[Cr(H_2O)_2(C_2O_4)_2]H_2O}$
b. Name the metal present in the complex compound of $(i)$ Haemoglobin $(ii)$ Vitamin $B-12$
View full solution →a. A soda bottle will go flat (loose its fizz) faster in Srinagar than in Delhi. Is this statement correct? Why or why not?
b. How does sugar help in increasing the shelf life of the product?
The equilibrium constant of cell reaction :
$Sn^{4+}(.aq) + Al(s) Al^{3+ }\rightarrow + Sn^{2+} (aq)$ is $4.617 \times 10^{184}, at 25 ^\circ C$
a. Calculate the standard emf of the cell. $($Given: $\log 4.617 \times 10^{184} = 184.6644)$
b. What will be the $E^\circ$ of the half cell $Al^{3+}/Al, if E^\circ$ of half cell $Sn^{4+}/Sn^{2+}$ is $4+ 0.15 V.$
View full solution →Various isomeric haloalkanes with the general formula $\ce{{C_4H_9CI}}$ undergo hydrolysis reaction. Among them, compound $"A "$ is the most reactive through $\ce{S_N^1}$ mechanism. Identify $"A "$ citing the reason for your choice. Write the mechanism for the reaction.
View full solution →Neeta was experimenting in the lab to study the chemical reactivity of alcohols. She carried out a dehydration reaction of propanol at $140^\circ C$ to $180^\circ C$. Different products were obtained at these two temperatures.
a. Identify the major product formed at $140^\circ C$ and the substitution mechanism followed in this case.
b. Identify the major product formed at $180^\circ C$ and the substitution mechanism followed in this case.
View full solution →a. Give the structure of all the possible dipeptides formed when the following two amino acids form a peptide bond.
b. Keratin, insulin, and myosin are a few examples of proteins present in the human body. Identify which type of protein is keratin and insulin and differentiate between them based on their physical properties.
An organic compound 'X', does not undergo aldol condensation. However 'X' with compound 'Y' in the presence of a strong base react to give the compound 1,3-diphenylprop-2-en-1-one.
a. Identify 'X' and 'Y'
b. Write the chemical reaction involved.
c. Give one chemical test to distinguish between X and Y.
Amines are basic in nature. The $pK_b$ value is a measure of the basic strength of an amine. Lower the value of $pK_b$ more basic is the amine. The effect of substituent on the basic strength of amines in aqueous solution was determined using titrations. The substituent $''X\ ''$ replaced $''-CH_2\ ''$ group in piperidine $($ compound $1)$ and propylamine $\ce{CH_3CH_2CH_2NH_2}, ($compound $2).$
Compound $1:$ 
Compound $2: \ce{HXCH_2CH_2NH_2}$
$($source: Hall $\text{Jr, H. K.} (1956).$ Field and inductive effects on the base strengths of amines. Journal of the American Chemical Society, $78(11), 2570-2572.)$
Study the above data and answer the following questions:
$a.$ Plot a graph between the electronegativity of the substituent vs $pK_b$ value of the corresponding substituted propyl amine $($given that $pK_a + pK_b =14).$ Is there any relation between the electronegativity of the substituent and its basic strength?
$b.$ The electronegativity of the substituent $''C_6H_5CON\ ''$ is $3.7,$ what is the expected $pKa$ value of compound $\ce{C_6H_5CONHCH_2CH_2NH_2}$?
$(i)\ 9.9\ (ii)\ 9.5\ (iii)\ 9.3\ (iv)\ 9.1$
$c.$ The pKa value of the substituted piperidine formed with substituent $''X\ ''$ is found to be $8.28.$ What is the expected electronegativity of $''X\ ''$
$(i)\ 3.5\ (ii)\ 3.4\ (iii)\ 3.8\ (iv)\ 3.1$ View full solution →What is the most suitable pKa value of the substituted propylamine formed with substituent "X" with electronegativity 3.0
(i)10.67 (ii)10.08 (iii) 10.15 (iv)11.10
What change in the concentration of H₂ will triple the rate of reaction?
(c). Suppose a reaction between A and B, was experimentally found to be first order with respect to both A and B. So the rate equation is:
Rate = k[A][B]
Which of these two mechanisms is consistent with this experimental finding? Why?
Mechanism 1
A → C + D (slow)
B+C → E (fast)
Mechanism 2
A+B →C + D (slow)
C → E (fast)
Dependence of the rate of reaction on the concentration of reactants, temperature, and other factors is the most general method for weeding out unsuitable reaction mechanisms. The term mechanism means all the individual collisional or elementary processes involving molecules $($atoms, radicals, and ions included$)$ that take place simultaneously or consecutively to produce the observed overall reaction. For example, when hydrogen gas reacts with bromine, the rate of the reaction was found to be proportional to the concentration of $H_2$ and to the square root of the concentration of $Br_2.$ Furthermore, the rate was inhibited by increasing the concentration of $HBr$ as the reaction proceeded. These observations are not consistent with a mechanism involving bimolecular collisions of a single molecule of each kind. The currently accepted mechanism is considerably more complicated, involving the dissociation of bromine molecules into atoms followed by reactions between atoms and molecules:
It is clear from this example that the mechanism cannot be predicted from the overall stoichiometry.
$($source: Moore, J. W., Pearson, $R. G. (1981).$ Kinetics and mechanism. John Wiley Sons.$)$
$(a).$ Predict the expression for the rate of reaction and order for the following:
$H_2 + Br_2 \rightarrow 2 HBr$
What are the units of rate constant for the above reaction?
$(b).$ How will the rate of reaction be affected if the concentration of $Br_2$ is tripled?
View full solution →$(a).$ While giving intravenous injections to the patients, the doctors take utmost care of the concentration of the solution used. Why is it necessary to check the concentration of the solution?
$(b). $ A solution of phenol was obtained by dissolving $2X 10^{-2} \ kg$ of phenol in $1 \ kg$ of benzene. Experimentally it was found to be $73\%$ associated. Calculate the depression in the freezing point recorded.
View full solution →$(a).$ A purple colour compound $A,$ which is a strong oxidising agent and used for bleaching of wool, cotton, silk and other textile fibres was added to each of the three test tubes along with $H_2SO_4.$ It was followed by strong heating.
In which of the above test tubes; $A, B$ or $C:$
$(i)$ Violet vapours will be formed
$(ii)$ The bubbles of gas evolved will extinguish a burning matchstick. Write an equation for each of the above observations.
$b. A$ metal ion $M^{n+}$ of the first transition series having $d^5$ configuration combines with three didentate ligands. Assuming $\Delta_0 < P:$
$(i)$ Draw the crystal field energy level diagram for the $3d$ orbital of this complex.
$(ii)$ What is the hybridisation of Mnt in this complex and why?
$(iii)$ Name the type of isomerism exhibited by this complex. View full solution →$(a).$ An experiment was carried out in the laboratory, to study depression in freezing point. $1M$ aqueous solution of $Al(NO_3)_3$ and $1\ M$ aqueous solution of glucose were taken. From the given figure identify solution $1$ and solution $2.$ Give a plausible reason for your answer
$(b).$ The osmotic pressure of a solution of cane sugar was found to be $2.46$ atm at $300 K.$ If the solution was diluted five times, calculate the osmotic pressure at the same temperature.
How can the osmotic pressure of the given cane sugar solution be decreased without changing its volume? Give a reason for your answer. View full solution →$(a).$ Out of formic acid and acetic acid, which one will give the $\text{HVZ}$ reaction? Give a suitable reason in support of your answer and write the chemical reaction involved.
$(b)$. Alcohols are acidic but they are weaker acids than water. Arrange various isomers of butanol in the increasing order of their acidic nature. Give a reason for the same.
$(c).$ An organic compound $A$ which is a Grignard reagent is used to obtain $2-$methylbutan$-2-ol$ on reaction with a carbonyl compound $'B\ '.$ Identify $A\ '$ and $'B\ '.$ Write the equation for the reaction between $A$ and $B.$
View full solution →$(a).$ Give reasons for the following:
$(i)$ The reaction of ethanol with acetyl chloride is carried out in the presence of pyridine. Cresols are less acidic than phenol. Williamson's process is used for the preparation of ethers from alkyl halide. Identify the alkyl bromide and sodium alkoxide used for the preparation of $2-$ Ethoxy$-3-$methylpentane
$(c).$ Convert:
$(i)$ Toluene to $3-$nitrobenzoic acid.
$(ii)$ Benzene to $m-$nitroacetophenone.
View full solution →