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Chemistry · PYQ NEET UG 2022
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Chemistry · Structure of atom
Given below are two statements:\n Statement I: Aufbau principle dictates that electrons fill orbitals in order of increasing energies.\n Statement II: Hund's rule states that pairing of electrons in orbitals belonging to the same subshell does not take place until each orbital is singly occupied. \nIn the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · PYQ NEET UG 2018
The CORRECT difference between first- and second-order reactions is that
Read answer →Chemistry · THERMODYNAMICS
Consider the following chemical reactions and statements regarding \( \Delta H \) and \( \Delta U \) at constant temperature: (A) For the reaction \( \text{C}(s) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \), \( \Delta n_g = 0 \), therefore \( \Delta H = \Delta U \). (B) For the reaction \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \), \( \Delta n_g = -2 \), therefore \( \Delta H < \Delta U \). (C) For the reaction \( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \), \( \Delta n_g = +1 \), therefore \( \Delta H > \Delta U \). (D) For an isochoric process with no non-expansion work, \( \Delta U = q_v \). How many of the above statements are correct?
Read answer →Chemistry · Classification of Elements and Periodicity in Properties
According to the IUPAC nomenclature system for elements with atomic number above 100, what is the numerical root for the digit 7 and its abbreviation?
Read answer →Chemistry · Structure of atom
What is the relative charge of an electron?
Read answer →Chemistry · PYQ NEET UG 2021
Tritium, a radioactive isotope of hydrogen emits which of the following particles?
Read answer →Chemistry · PYQ NEET UG 2026
Match the species in List I with their geometry in List II List I List II A \( \text{PCl}_5 \) I. Tetrahedral B \( \text{BrF}_5 \) II. Square Planar C \( \text{BF}_4^- \) III. Trigonal bipyramidal D \( [\text{Ni(CN)}_4]^{2-} \) IV. Square pyramidal Choose the correct answer from the options given below:
Read answer →Chemistry · THERMODYNAMICS
For the reaction \( \text{Fe}_2\text{O}_3(s) + 3\text{H}_2(g) \rightarrow 2\text{Fe}(s) + 3\text{H}_2\text{O}(l) \), the standard enthalpy change is \( \Delta_r H_1^\ominus = -33.3\text{ kJ mol}^{-1} \). What is the standard enthalpy change \( \Delta_r H_2^\ominus \) for the reaction: \( \frac{1}{2}\text{Fe}_2\text{O}_3(s) + \frac{3}{2}\text{H}_2(g) \rightarrow \text{Fe}(s) + \frac{3}{2}\text{H}_2\text{O}(l) \)?
Read answer →Chemistry · Some Basic Concepts of Chemistry
Hydrogen combines with oxygen to form two compounds, namely water and hydrogen peroxide. The masses of oxygen which combine with a fixed mass of hydrogen (\( 2 \text{ g} \)) are \( 16 \text{ g} \) and \( 32 \text{ g} \), respectively. This ratio (\( 16:32 = 1:2 \)) is an illustration of which law?
Read answer →Chemistry · THERMODYNAMICS
Starting from the Gibbs function \( G = H - TS \), which differential relation holds true for a finite change at constant temperature?
Read answer →Chemistry · PYQ NEET UG 2021
The structures of beryllium chloride in solid state and vapour phase are _______.
Read answer →Chemistry · Structure of atom
Which of the following fundamental equations in quantum mechanics represents the Schrödinger wave equation involving the Hamiltonian operator \( \hat{H} \)?
Read answer →Chemistry · PYQ NEET UG 2022
The pollution due to oxides of sulphur gets enhanced due to the presence of: (i) particulate matter (ii) ozone (iii) hydrocarbons (iv) hydrogen peroxide Choose the most appropriate answer from the options given below:
Read answer →Chemistry · EQUILIBRIUM
The molar solubility of zirconium phosphate, \( \text{Zr}_3(\text{PO}_4)_4 \), in pure water is \( S\text{ mol L}^{-1} \). The solubility product constant \( K_{sp} \) in terms of \( S \) is:
Read answer →Chemistry · PYQ NEET UG 2016(2)
Which one of the following nitro compounds does NOT react with nitrous acid?
Read answer →Chemistry · PYQ NEET UG 2017
Identify A and predict the type of reaction.\n(Reaction: Chloro/bromo anisole with \( \text{NaNH}_2 \) yielding substitution product)
Read answer →Chemistry · PYQ NEET UG 2024
The highest number of helium atoms is in
Read answer →Chemistry · THERMODYNAMICS
Match List-I with List-II: List-I (Chemical Reaction) List-II (Enthalpy vs Internal Energy Relation) A \( \text{C}(s) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \) I \( \Delta H = \Delta U - RT \) B \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \) II \( \Delta H = \Delta U + RT \) C \( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \) III \( \Delta H = \Delta U \) D \( \text{H}_2(g) + \frac{1}{2}\text{O}_2(g) \rightarrow \text{H}_2\text{O}(g) \) IV \( \Delta H = \Delta U - 2RT \) Choose the correct answer from the options given below:
Read answer →Chemistry · PYQ NEET UG 2020
HI के साथ विदलन पर ऐनिसोल देता है _______।
Read answer →Chemistry · THERMODYNAMICS
Why is the absolute value of internal energy (\( U \)) of a system impossible to determine, whereas the change in internal energy (\( \Delta U \)) is readily measurable?
Read answer →Chemistry · THERMODYNAMICS
Consider the combustion of liquid benzene: \( 2\text{C}_6\text{H}_6(l) + 15\text{O}_2(g) \rightarrow 12\text{CO}_2(g) + 6\text{H}_2\text{O}(l) \) at \( 298\text{ K} \). The difference between the enthalpy of reaction and internal energy change, \( (\Delta H - \Delta U) \), per mole of benzene combusted is: (Take \( R = 8.314\text{ J}\cdot\text{K}^{-1}\cdot\text{mol}^{-1} \))
Read answer →Chemistry · Some Basic Concepts of Chemistry
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In the multiplication of \( 2.5 \) and \( 1.25 \), the final reported result is \( 3.1 \) rather than \( 3.125 \). Reason (R): In multiplication or division, the final result must not have more significant figures than the measurement with the fewest significant figures. In the light of the above statements, choose the correct answer from the options given below:
Read answer →Chemistry · PYQ NEET UG 2017
