List of top Chemistry Questions

Consider the following sequence of reactions to produce major product (A):

The molar mass of the product (A) is g mol−1. (Given molar mass in g mol−1 of C: 12,
H: 1, O: 16, Br: 80, N: 14, P: 31)

The standard enthalpy and standard entropy of decomposition of $ N_2O_4 $ to $ NO_2 $ are 55.0 kJ mol$^{-1}$ and 175.0 J/mol respectively. The standard free energy change for this reaction at 25°C in J mol$^{-1}$ is (Nearest integer)

The Maximum number of RBr producing 2-methylbutane by above sequence of reaction

The correct statements from the following are :
(A) $ Tl^{3+} $ is a powerful oxidising agent
(B) $ Al^{3+} $ does not get reduced easily
(C) Both $ Al^{3+} $ and $ Tl^{3+} $ are very stable in solution
(D) $ Tl^+ $ is more stable than $ Tl^{3+} $
(E) $ Al^{3+} $ and $ Tl^+ $ are highly stable
Choose the correct answer from the options given below :

In $ SO_2 $, $ NO_2^- $ and $ N_3^- $ the hybridizations at the central atom are respectively :

Match List-I with List-II

Choose the correct answer from the options given below :

'X' is the number of acidic oxides among $ VO_2, V_2O_3, CrO_3, V_2O_5 $ and $ Mn_2O_7 $. The primary valency of cobalt in $ [Co(H_2NCH_2CH_2NH_2)_3]_2 (SO_4)_3 $ is Y. The value of X + Y is :

Liquid A and B form an ideal solution. The vapour pressure of pure liquids A and B are 350 and 750 mm Hg respectively at the same temperature. If $ x_A $ and $ x_B $ are the mole fraction of A and B in solution while $ y_A $ and $ y_B $ are the mole fraction of A and B in vapour phase then :

The correct statement amongst the following is :

20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is ___ x $ 10^{-2} $ M. (Nearest integer)

Consider the following cases of standard enthalpy of reaction ($ \Delta H_f^\circ $ in kJ mol$^{-1}$): \[ \text{C}_2\text{H}_6(g) + 7 \text{O}_2(g) \rightarrow 2 \text{CO}_2(g) + 3 \text{H}_2\text{O}(l) \quad \Delta H_1^\circ = -1550 \] \[ \text{C(graphite)} + \text{O}_2(g) \rightarrow \text{CO}_2(g) \quad \Delta H_2^\circ = -393.5 \] \[ \text{H}_2(g) + \frac{1}{2} \text{O}_2(g) \rightarrow \text{H}_2\text{O}(g) \quad \Delta H_3^\circ = -286 \] The magnitude of $ \Delta H_f^\circ $ of $ \text{C}_2\text{H}_6(g) $ is ____ kJ mol$^{-1}$ (Nearest integer).

The species which does not undergo disproportionation reaction is:

Niobium (Nb) and ruthenium (Ru) have "x" and "y" number of electrons in their respective 4d orbitals. The value of $ x + y $ is:

Given below are two statements: Statement (I): \textit{Nitrogen, sulphur, halogen, and phosphorus present in an organic compound are detected by Lassaigne's Test.}
Statement (II): \textit{The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test.} In the light of the above statements, choose the correct answer from the options given below:

Identify the number of structure/s from the following which can be correlated to D-glyceraldehyde.

Given below are two statements:
Statement (I): A spectral line will be observed for a $2p_x \rightarrow 2p_y$ transition.
Statement (II): $2p_x$ and $2p_y$ are degenerate orbitals.

In the light of the above statements, choose the correct answer from the options given below:

Identify the homoleptic complex(es) that is/are low spin.

When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is:

The molar solubility(s) of zirconium phosphate with molecular formula $ \text{Zr}^{4+} \text{PO}_4^{3-} $ is given by relation:

Given below are two statements: Statement (I): \textit{Corrosion is an electrochemical phenomenon in which pure metal acts as an anode and impure metal as a cathode.}
Statement (II): \textit{The rate of corrosion is more in alkaline medium than in acidic medium.} In the light of the above statements, choose the correct answer from the options given below:

Pair of transition metal ions having the same number of unpaired electrons is :

1 Faraday electricity was passed through Cu$^{2+}$ (1.5 M, 1 L)/Cu and 0.1 Faraday was passed through Ag$^+$ (0.2 M, 1 L) electrolytic cells. After this, the two cells were connected as shown below to make an electrochemical cell. The emf of the cell thus formed at 298 K is:

Given: $ E^\circ_{\text{Cu}^{2+}/\text{Cu}} = 0.34 \, \text{V} $ $ E^\circ_{\text{Ag}^+/ \text{Ag}} = 0.8 \, \text{V} $ $ \frac{2.303RT}{F} = 0.06 \, \text{V} $

Thyroxine, the hormone has the given structure. The percentage of iodine in thyroxine is ............... % (nearest integer). (Given molar mass in g mol$^-$ C:12, H:1, O:16, N:14, I:127)

Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.