List of top Chemistry Questions asked in GATE CY

In the scheme \( \mathrm{P_2} \xrightleftharpoons[\;k_1\;]{\;I_a\;} 2\mathrm{Q} \xrightarrow{k_2} \mathrm{R} \), \(I_a\) represents the intensity of light absorbed. Assuming the quantum yield of the first step is one, the steady-state concentration of \(\mathrm{Q}\) is given by

In the \(^{1}\)H NMR spectrum, multiplicity of the signal (bold and underlined H atom) in the following species is
(I) \([\mathbf{H}\mathrm{Ni(OPEt_3)_4}]\)^{+}
(II) \(\mathrm{Ph_2Si(Me)\underline{\mathbf{H}}}\)
(III) \(\mathrm{PH_3}\)
(IV) \((\mathrm{Cp^*})_2\mathrm{Zr\underline{\mathbf{H}}_2}\) (Cp\(^*\)=pentamethylcyclopentadienyl)

M and N in the given reaction scheme are (Simmons–Smith on the alkene, then OsO\(_4\)/NMO):

A compound, \(\mathrm{C_{15}H_{16}O_2}\), has the following spectral data;
\(^1\)H NMR (ppm): 9.16 (s), 6.89 (d, \(J = 8\) Hz), 6.64 (d, \(J = 8\) Hz), 1.53 (s)
\(^ {13}\)C NMR (ppm): 154.7, 140.9, 127.1, 114.4, 40.7, 30.7
The structure of the compound is

E and F in the given reaction scheme are determined for the photolysis (\(h\nu\)) of the fused N–O heterocycle bearing an N-phenyl group, followed by thermolysis (\(\Delta\)).

The major product formed in the given reaction sequence is

The calculated magnetic moment of [Ce(NO₃)₅]^2- is ........... BM (rounded off to two decimal places).
(Given: atomic number of Ce is 58)

The choice(s) that correctly identify radioisotopes (P, Q, R, S) shown in the following nuclear reaction is(are):
\[ ^{60}_{28}\text{Ni} + \alpha \;\; \longrightarrow \;\; P \; (\text{unstable}) \] \[ P \;\longrightarrow\; n + Q, \qquad P \;\longrightarrow\; 2n + R, \qquad P \;\longrightarrow\; p + n + S \]

Product(s) formed in the given reaction is(are):

For the Lindemann–Hinshelwood mechanism of gas phase unimolecular reactions, the true statement(s) is(are)

Point group of naphthalene (C₁₀H₈) is

The organometallic catalyst for the following transformation is (intramolecular olefin closure giving a cyclohexene and ethylene, i.e., ring-closing metathesis):

The magnitudes of CFSE in \([\mathrm{M}(\mathrm{H}_2\mathrm{O})_6]^{n+}\) for Mn and Fe ions satisfy the relations

Assertion (S): The total angular momentum for light atoms (low atomic number) is obtained by Russell–Saunders coupling, whereas \(jj\)-coupling is used for heavy atoms (high atomic number).
Reasoning (R): The spin–orbit interactions are weak in light atoms (low atomic number) and strong in heavy atoms (high atomic number).
The correct option is

For an ideal gas, the molecular partition function in the canonical ensemble, that is proportional to the system volume (V), is the

The INCORRECT statement is

The major product formed in the following reaction is \(\; \mathrm{nBu_3SnH,\ AIBN,\ C_6H_6,\ heat}\)

Compound \(\mathbf{P}\) was prepared based on a four-component reaction at room temperature in methanol. The required starting materials for the synthesis are (structure of \(\mathbf{P}\) shown).

On irradiation using UV light (\(>300\) nm), compounds X and Y predominantly undergo which photochemical pathway? (Structures as shown in the figure)

The major product formed when the \(\,o\)-(\(\mathrm{Me_3Si}\))-aryl triflate (a Kobayashi benzyne precursor) is treated with Ph–substituted cyclohexene in the presence of \(\mathrm{CsF}\) in \(\mathrm{CH_3CN}\) at r.t. is (A)–(D) as shown in the figure.

The compound which gives a fragment at \(m/z = 124 [M+H]^+\) is:

The major product formed in the given reaction is