List of top Chemistry Questions on Physical Chemistry asked in JEE Main

Compound (X) has molar mass \(76\). \(2 \times 10^{-3}\) mole of X gives \(0.4813\,g\) \(BaSO_4\) as precipitate. What is the % of S in compound (X)? Mention answer in \(10^{-1}\) form.

For the reaction: \[ R \rightarrow P \] The variation of concentration of reactant \([R]\) with time is shown below. Statements: I. Curve 1 will be observed when order of reaction is 1. II. If curve 2 & curve 3 are observed for \(1^{st}\) order then rate constant for \(3^{rd}\) curve will be greater than rate constant for \(2^{nd}\) curve. III. Decomposition of HI on gold surface represent curve (1). Select the option representing correct set of statements: 

Consider the following setup separated by a semi–permeable membrane (SPM): Left compartment (x): \(K_4[Fe(CN)_6]\) solution \(0.1\,M\), \(100\,ml\) Right compartment (y): \(FeCl_3\) solution \(0.1\,M\), \(100\,ml\) Which of the following is correct for the above figure?

From given data (I) 90.8 lit of \(H_2(g)\) at STP (II) 684 gm of sucrose (III) 2 moles of cyclohexane Correct order of total number of atoms will be
When 3.395 gm \(C_2H_5OH_{(l)}\) is burnt completely, it liberates 101.11 kJ of heat, then find the enthalpy of formation of \(C_2H_5OH_{(l)}\). Given: \(\Delta H_f^\circ\) of \(H_2O_{(l)} = -285.8 \, \text{kJ/mol}\) \(\Delta H_c^\circ\) of graphite \(= -393.5 \, \text{kJ/mol}\)
For a given reversible reaction at \(300\,K\): \[ 2\text{N}_2\text{O}_5(g) \rightleftharpoons 4\text{NO}_2(g) + \text{O}_2(g) \] If \( \text{N}_2\text{O}_5 \) is 50% dissociated at 5 bar and 300 K at equilibrium, then find \( \Delta G^\circ \) for the reaction? [Given: \( \log 2 = 0.3,\ \log 7 = 0.84 \)]
20 ml of CH\(_3\)COOH solution is neutralised by 28.08 ml of NaOH. In the 20 ml of same solution 14.04 ml of same NaOH solution is poured, then pH of resultant solution will be: (pKa of CH\(_3\)COOH = 4.75)
Given that: \[ E^\circ_{\text{Fe}^{3+}/\text{Fe}} = -0.036\, \text{V} \quad \text{and} \quad E^\circ_{\text{M}^{x+}/\text{M}} = 0.15\, \text{V} \] A Galvanic cell is formed using above electrodes, whose \( E_{\text{cell}} = 0.2047\, \text{V} \) when reaction quotient of cell reaction is \(10^{-2}\). Find the value of \(x\). [Nearest integer]
For the first order reaction \[ A \rightarrow P \] Based on the given data, find the time \(x\) (in min):

Given:
\(t = 0 \, \text{min} \Rightarrow [A] = 0.625 \, M\)
\(t = x \, \text{min} \Rightarrow [A] = 0.0625 \, M\)
\(t = 20 \, \text{min} \Rightarrow [A] = 0.00625 \, M\)
If the Bohr's radius of H-atom is 52.9 pm and radius of H-like species is 70.53 pm, then chemical species and orbit number are respectively.
0.2M, 500ml MnO\(_4^-\) solution is treated with 1.5M, 500ml KI solution in basic medium. The liberated \(I_2\) required ‘X’M, 300ml hypo solution. The value of ‘X’ is -
Statement I: Of the following compounds \( SO_2, SO_3, H_2S, SF_4 \); only three compounds have a complete octet.
Statement II: For the given set of compounds \([SF_4, BrF_5, ClF_3], [NH_3, BrF_5, SF_4], [H_2O, IF_5, XeF_4]\) only one set of compounds has one lone pair on all central atoms.
Consider the following ionization energy order
(A) IE₁: Cr > Mn
(B) IE₂: Cr < Mn
(C) IE₁: Cr < Mn
(D) IE₂: Cr > Mn
Correct order among the following:
‘X’ is the nitrogen containing compound which is added to freshly prepared FeSO\(_4\) and dilute H\(_2\)SO\(_4\) to form a brown ring complex ‘Y’.
Identify X and Y.
Statement I: The bond angle order in \( OF_2, H_2O, OCl_2 \) is \( OF_2<H_2O<OCl_2 \)
Statement II: \( SiF_4, SnF_4, \) and \( PbF_4 \) are all ionic compounds.
Column-I (Isothermal process)
Statement I: \( \mathrm{ClO_4^-} \), \( \mathrm{ICl_4^-} \), \( \mathrm{IBr_2^-} \) are tetrahedral, square planar and linear respectively.
Statement II: \( \left[\mathrm{Fe(CN)_6}\right]^{4-} \) is \( \mathrm{d^2sp^3} \) hybridized.
For the reaction \(A \longrightarrow \text{Product}\), the following graph is observed between half life \((t_{1/2})\) and initial concentration of \(A\). Then find the value of \(x\).
For the complex ion with configurations \(d^3\), \(d^4\) (low spin), \(d^5\) (high spin), \(d^7\) (low spin) and \(d^6\) (high spin), the total number of unpaired electrons is _ _ _ _ _ _ _ _ _ _ _ _ .
Molar conductivity and conductance of an electrolytic solution are 123.5 Scm$^2$/mole and 0.19 S respectively. Concentration of solution is $x$% w/w, then find the value of x.
(cell constant = 1.3 S cm$^{-1}$; density of solution = 1 gm/ml; molar mass of electrolyte = 75 g/mole)
Silver rod is dipped in aqueous solution of \( \mathrm{AgNO_3} \) of unknown concentration and Zn rod is dipped in \( 1 \, \mathrm{M} \) \( \mathrm{ZnSO_4} \) aqueous solution. Both these containers are connected to form a galvanic cell showing emf of \( 1.6 \, \mathrm{V} \). Calculate the value of \( \log_{10}[\mathrm{Ag}^+] \).
\( E^\circ_{\mathrm{Ag^+/Ag(s)} = 0.8 \, \mathrm{V} \qquad E^\circ_{\mathrm{Zn^{2+}/Zn(s)}} = -0.76 \, \mathrm{V} \)
[Use \( \dfrac{2.303RT}{F} = 0.059 \)]
For the given reaction:
\[ \mathrm{X_2(g) + Y_2(g) \rightleftharpoons 2XY(g)} \] The following data table is provided at \(600 \, \mathrm{K}\):
& \(\Delta_f H \, (\mathrm{kJ/mol})\) & \(S_m \, (\mathrm{J\,K^{-1}\,mol^{-1}})\)
\(\mathrm{X_2}\) & 80 & 140
\(\mathrm{Y_2}\) & 8 & 250
\(\mathrm{XY}\) & 42 & 200
\endtabular Calculate \(\Delta_r G\) at \(600 \, \mathrm{K}\).
For the reaction:
\[ \text{A(g)} \rightleftharpoons \text{B(g)} + \text{C(g)} \] Initial moles of A(g) is \(a\). At equilibrium, \(x\) moles of A decompose at total pressure \(P\). Calculate \(K_P\) for the given reaction.
Consider the following equilibrium: \[ 2AB \rightleftharpoons A_2 + B_2 \] If equilibrium pressure is \(P\) and degree of dissociation is \(\alpha\), then \(K_p\) is
Consider the following electrochemical cell \[ Zn | Zn^{2+}(aq) \, || \, Ag^{+}(aq) | Ag \] \[ [Zn^{2+}] = 1\,M \] The \(E_{cell\) was found to be \(1.6\,V\). The value of \(\log[Ag^+]\) is \[ E^\circ_{Zn^{2+}/Zn} = -0.76\,V , \qquad E^\circ_{Ag^+/Ag} = +0.80\,V \]