List of top Chemistry Questions on Physical Chemistry asked in IISER

600 K पर, 191.47 kJ mol-1 की सक्रियण ऊर्जा के साथ एक अभिक्रिया का वेग स्थिरांक $5.0 \times 10^{-5}$ s-1 है। किस तापमान पर इस अभिक्रिया की अर्धायु 152 s होगी? [पूर्व-चरघातांकी गुणक तथा सक्रियण ऊर्जा को तापमान पर निर्भर नहीं मानिए। R = 8.314 J K-1 mol-1]

दो शुद्ध वाष्पशील द्रवों X एवं Y के लिए, X-X और Y-Y दोनों की अंतरआण्विक आकर्षण अन्योन्यक्रियाएं (attractive intermolecular interactions) X-Y की तुलना में कम हैं। X एवं Y के एक सममोलर विलयन का कुल वाष्पदाब ptotal है। शुद्ध X एवम् शुद्ध Y का वाष्पदाब क्रमशः $p_X^0$ और $p_Y^0$ है। नीचे दिए गये संबंधों में से कौन सा एक विकल्प सही है?

Be3+ के चतुर्थ कक्ष में एक इलेक्ट्रॉन के वेग तथा He+ के द्वितीय कक्ष में एक इलेक्ट्रॉन के वेग का अनुपात क्या होगा?

एक आदर्श गैस पहले एक उत्क्रमणीय समतापीय प्रसरण (reversible isothermal expansion) (सॉलिड रेखा) से गुजरती है। तत्पश्चात वह आदर्श गैस उत्क्रमणीय रुधोष्म प्रसरण (reversible adiabatic expansion) (बिन्दुयुक्त रेखा) से गुजरती है। नीचे दिए गए रेखा चित्र/चित्रों में से कौन से इस समस्त प्रक्रम को बारीकी से दर्शाता है/दर्शाते हैं?

1.0 M NaOH के जलीय विलयन के 100 mL को जल मिलाकर 1.0 L तक तनु किया जाता है। इस विलयन का आधा हिस्सा फेंक दिया जाता है। बचे हुए विलयन में एक नए 0.5 M NaOH के जलीय विलयन का 100 mL मिलाया जाता है। इस अंतिम NaOH के जलीय विलयन की सांद्रता क्या होगी?

जलीय अम्लीय माध्यम में, [Cr2O7]2− का Cr3+ में अपचयन करने के लिए क्रमशः कितने प्रोटोनों (H+) एवं इलेक्ट्रॉनों (e−) की आवश्यकता होगी?

The rate constant of a reaction at 600 K with an activation energy of 191.47 kJ mol$^{-1}$ is 5.0 $\times$ 10$^{-5}$ s$^{-1}$. What is the temperature at which the half-life of the reaction becomes 152 s? [Consider pre-exponential factor and activation energy to be independent of temperature. R = 8.314 J K$^{-1}$mol$^{-1}$]}

For two pure volatile liquids X and Y, attractive intermolecular interactions of both X-X and Y-Y are weaker than those of X-Y. The total vapour pressure of an equimolar solution of X and Y is p$_{\text{total}$. The vapour pressure of pure X and pure Y are p$^0_{\text{X}}$ and p$^0_{\text{Y}}$, respectively. Which one of the following relations is correct?

What is the ratio of the velocity of an electron in the fourth orbit of Be$^{3+}$ to the velocity of the electron in the second orbit of He$^{+}$?

100 mL of 1.0 M aqueous NaOH solution was diluted to 1.0 L by adding water. Half of this solution was discarded. A new 100 mL of 0.5 M aqueous NaOH solution was added to the remaining solution. What is the concentration of the final aqueous NaOH solution?

What is the order of pK$_b$ for the following molecules in an aqueous medium?

Which one of the following octahedral complexes has the highest spin-only magnetic moment?

The dipole moments of three $\text{AB}_3$-type molecules I, II, and III are measured to be 0.0 D, 0.2 D, and 1.5 D, respectively. Which one of the following options is correct regarding the identity of I, II, and III?

At a particular temperature, the magnitude of the rate constant of a reaction is $5 \times 10^{-5}$ and the unit of the pre-exponential factor of the Arrhenius equation for this reaction is $\text{mol L}^{-1}\text{ min}^{-1}$. Which of the following plots is correct for this reaction?
[Note: $[\text{R}]_0$ is the initial concentration and $\text{t}_{1/2}$ is the half-life of the reaction]}

The work done when one mole of an ideal gas expands at constant temperature $T$ from volume $V$ to $2V$ (in two equal steps of volume in a linear fashion) is $\frac{7}{12}RT$. How much more work would be done by the gas if it expands in three equal steps?
(R is the universal gas constant)}

Compound I undergoes hydroboration-oxidation reaction with $(\text{BH}_3)_2$ followed by treatment with $\text{H}_2\text{O}_2$ and aqueous $\text{NaOH}$ to produce another compound II, which upon oxidation with $\text{CrO}_3$ gives 2,3-dimethyl-cyclohexanone as the product. What is the structure of I?

What is the value of $E^\circ(\text{Fe}^{3+}/\text{Fe}^0)$?
(The standard reduction potential values are $E^\circ(\text{Fe}^{3+}/\text{Fe}^{2+}) = 0.77\text{ V}$, and $E^\circ(\text{Fe}^{2+}/\text{Fe}^0) = -0.44\text{ V}$)}

Consider an exothermic reaction:
2A(s) \(\longrightarrow\) B(s) + C(g) + D(g)
The correct statement about the reaction is

The minimum energy needed to remove an electron from a metal corresponds to a wavelength of 500 nm. What is the total kinetic energy of all the photoelectrons ejected per second when the entire radiation from a 100 Watt bulb with a wavelength of 300 nm falls on the surface of the metal?
Planck’s constant = 6.6 \(\times 10^{-34}\) J s; speed of light = 3 \(\times 10^8\) m s\(^{-1}\)

For a reaction R \(\longrightarrow\) P with a rate constant of 3 \(\times 10^{-3}\) mol L\(^{-1}\) s\(^{-1}\), which one of the following plots is correct?

Which one of the following plots correctly describes the variation of osmotic pressure (H) of a fixed amount of a solute against the volume (V) of the solution at a fixed temperature?

Consider the following data for KCl solution at a particular temperature:

What is the value of the limiting molar conductivity?