List of top Chemistry Questions

Standard electrode potential for Sn$^{4+}$/Sn$^{2+}$ couple is +0.15 V and that for the Cr$^{3+}$/Cr couple is -0.74 V. The two couples in their standard states are connected to make a cell. The cell potential will be:

Why is a solution of $\text{Ni(H}_2\text{O})_6^{2+}$ green while a solution of $\text{Ni(CN)}_4^{2-}$ is colourless? (At. No. of Ni = 28)

Convert Propanoic acid to Ethane

Methyl fluoride is prepared by heating methyl bromide in the presence of AgF. This reaction is known as

The CORRECT order of boiling points for the hydrogen halides is:

The CORRECT statement(s) regarding biomolecules is(are):

Addition of a few drops of concentrated HCl to an aqueous solution of CoCl₂ forms a dark blue complex X.
The CORRECT statement(s) for this reaction is(are):
(Given: Atomic number of Co: 27)

The CORRECT statement(s) for the given reactions is(are):

For product formation from only one type of reactant (e.g. A $\rightarrow$ product), the CORRECT match for the order of the reaction (given in Column I) with the half-life expression (given in Column II) is:
($[A]_0 $ is the initial concentration and $ k_r $ is the rate constant)

A few species are given in Column I. Column II contains the hybrid orbitals used by the central atom of the species for bonding.
The CORRECT match for the species to their central atom hybridization is:
(Given: Atomic numbers of B: 5; C: 6; O: 8; F: 9; P: 15; Cl: 17; I: 53)

The CORRECT statement(s) about $[Ni(CN)_4]^{2-}$, $[Ni(CO)_4]$ and $[NiCl_4]^{2-}$ is(are):
(Given: Atomic number of Ni = 28)

The CORRECT statement(s) regarding the given molecules is(are):

The isothermal expansion of one mole of an ideal gas from $ V_i $ to $ V_f $ at temperature $ T $ occurs in two ways:
Path I: a reversible isothermal expansion;
Path II: free expansion against zero external pressure.
The CORRECT option for the values of $ \Delta U $, $ q $, and $ w $ for Path I and Path II is:

The standard enthalpy of the reaction, \[ \text{C (graphite)} + \text{H}_2\text{O (g)} \rightarrow \text{CO (g)} + \text{H}_2\text{ (g)} \text{ is found to be } +131.3 \, \text{kJ mol}^{-1} \] and the $ \Delta_f H^\circ $ value for CO (g) is -110.5 kJ mol⁻¹.
The value of $ \Delta_f H^\circ $ (in kJ mol⁻¹) for H₂O (g) is:

The rate of solvolysis for the following tertiary halides in 80% aqueous ethanol at 25°C follows the order:

A non-volatile solute has a molecular weight of 180 g mol$^{-1}$. Assume that the solute does not associate or dissociate in water, and the boiling-point constant (ebullioscopic constant) of water is 0.51 K kg mol$^{-1}$.
The amount (in g) of solute added to 500 g of water to elevate the boiling point by 0.153 K is ............... (answer in integer)

Energy of the transition from $ n_h = 4 $ to $ n_l = 2 $ for hydrogen atom is $ E \times 10^3 $ cm$^{-1}$.
Given: Rydberg constant for hydrogen: $ 1.097 \times 10^7 \, {m}^{-1} $
Value of E is ............... (rounded off to two decimal places)

The standard potentials ($ E^\circ $) for the Fe$^{3+}$/Fe and Fe$^{3+}$/Fe$^{2+}$ couples are -0.04 V and +0.76 V, respectively.
Given: Faraday constant = 96500 C mol$^{-1}$
The value for $ E^\circ $ (Fe$^{2+}$/Fe) in V is ............... (rounded off to two decimal places)

Consider the two $ pK_a $ values of valine as 2.32 and 9.62. The isoelectric point (pI) of this amino acid is ....... (rounded off to two decimal places)

The temperature dependence of reaction rates is generally given by the Arrhenius equation. A plot of $ \ln k_r $ against $ 1/T $ is a straight line from which the pre-exponential factor ‘$ A $’ and the activation energy ‘$ E_a $’ can be determined.
The CORRECT option regarding this plot is:

The bond order in $ N_2^{2-} $ species is:

The correct order of decreasing acidity of the following aliphatic acids is:

Identify the correct orders against the property mentioned:
A. H$_2$O $>$ NH$_3$ $>$ CHCl$_3$ - dipole moment
B. XeF$_4$ $>$ XeO$_3$ $>$ XeF$_2$ - number of lone pairs on central atom
C. O–H $>$ C–H $>$ N–O - bond length
D. N$_2$>O$_2$>H$_2$ - bond enthalpy
Choose the correct answer from the options given below:

The correct order of the wavelength of light absorbed by the following complexes is:
A. $[ \text{Co(NH}_3\text{)}_6]^{3+}$
B. $[ \text{Co(CN)}_6]^{3-}$
C. $[ \text{Cu(H}_2\text{O)}_4]^{2+}$
D. $[ \text{Ti(H}_2\text{O)}_6]^{3+}$
Choose the correct answer from the options given below:

Higher yield of NO in the reaction
N$_2$ (g) + O$_2$ (g) $\rightarrow$ 2NO (g)
can be obtained at [$\Delta H$ of the reaction = +180.7 kJ mol$^{-1}$]