Chemistry
GATE CY exam:gate PYQs
Build your understanding with focused practice from past exam papers.
Questions 511–520 of 650. Imported answers require independent review unless marked reviewed.
Question 46
Open questionCYNAT2 marksNeeds review
The specific rotation of optically pure (R)-2-bromobutane is −112.00. A given sample of 2-bromobutane exhibited a specific rotation of −82.88. The percentage of (S)-(+)-enantiomer present in this sample is ________.
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Open questionCYNAT2 marksNeeds review
Consider the following two parallel irreversible first order reactions at temperature T,
P → Q (k₁)
P → R (k₂)

where k₁ and k₂ are the rate constants and their values are 5 × 10⁻² and 15 × 10⁻² min⁻¹, respectively, at temperature T. If the initial concentration of the reactant ‘P’ is 4 mol L⁻¹, then the concentration of product ‘R’ after 10 min of reaction is ______ mol L⁻¹. (Round off to two decimal places)
(Assume only P is present at the beginning of the reaction.)
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Consider the following equilibrium
At 298 K, the standard molar Gibbs energies of formation, ΔfG°, of SO₂(g) and SO₃(g) are −300 and −371 kJ mol⁻¹, respectively. The value of the equilibrium constant, Kₚ, at this temperature is ______ × 10¹⁰. (Round off to the nearest integer)
(Gas constant R = 8.31 J mol⁻¹ K⁻¹)
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Open questionCYNAT2 marksNeeds review
Consider the electrochemical cell
M(s)|M₂(s)|M₂(aq)|M(s)
where ‘M’ is a metal. At 298 K, the standard reduction potentials are E°M²⁺(aq)/M(s) = −0.12 V, E°M₂(s)/M(s) = 0.36 V and the temperature coefficient is (∂E°cell/∂T)ₚ = 1.5 × 10⁻⁴ V K⁻¹. At this temperature the standard enthalpy change for the overall cell reaction, ΔrH°, is ______ kJ mol⁻¹. (Round off to two decimal places)
(Faraday constant F = 96500 C mol⁻¹)
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The normal boiling point of a compound (X) is 350 K (heat of vaporization, ΔvapH = 30 kJ mol⁻¹). The pressure required to boil ‘X’ at 300 K is ______ Torr. (Round off to two decimal places)
(Ignore the temperature variation of ΔvapH; Gas constant R = 8.31 J mol⁻¹ K⁻¹ and 1 atm = 760 Torr)
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For a bimolecular gas phase reaction P + Q → R, the pre-exponential factor is 1 × 10¹³ dm³ mol⁻¹ s⁻¹. The standard entropy of activation at 25 °C is ______ J K⁻¹ mol⁻¹. (Round off to two decimal points)
(The standard concentration c° = 1 mol dm⁻³, Planck constant h = 6.62 × 10⁻³⁴ J s; Boltzmann constant kB = 1.38 × 10⁻²³ J K⁻¹; Gas constant R = 8.31 J mol⁻¹ K⁻¹)
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Character table of point group D₈ is given below.
D₈ | E | 2C₈ | 2C₄ | 2C₈³ | C₂ | 4C₂′ | 4C₂″ |
|---|---|---|---|---|---|---|---|
A₁ | a | 1 | 1 | 1 | 1 | 1 | 1 |
A₂ | b | 1 | 1 | 1 | 1 | h | i |
B₁ | c | −1 | 1 | −1 | 1 | 1 | j |
B₂ | d | −1 | 1 | −1 | 1 | −1 | 1 |
E₁ | e | √2 | 0 | −√2 | −2 | 0 | 0 |
E₂ | f | 0 | −2 | 0 | k | 0 | 0 |
E₃ | g | −√2 | 0 | √2 | −2 | 0 | 0 |
Value of (a + b + c + d + e + f + g + h + i + j + k) is equal to ________
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If
, where
and
are spin angular momentum operators and
is spin up eigen function, then the value of ‘a’ is ________. (Round off to one decimal place)Log in to check the answer
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Open questionCYNAT2 marksNeeds review
A particle in one dimensional box of length
with potential energy
is perturbed by the potential
eV, where
is a constant. The 1st order correction to the 1st excited state of the system is __________ ×
eV.Log in to check the answer
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Open questionCYNAT2 marksNeeds review
Consider a two dimensional harmonic oscillator with angular frequency
. The wavelength of x polarized light required for the excitation of a particle from its ground state to the next allowed excited state is ________ ×
m. (Round off to one decimal place)(Speed of light
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