List of top Chemistry Questions

Arrange the following alkenes in the decreasing order of stability:
 
Choose the correct answer from the options given below: 
 

Given below are two statements:
Statement I: The second ionisation enthalpy of Na is larger than the corresponding ionisation enthalpy of Mg.
Statement II: The ionic radius of $O^{2-$ is larger than that of $F^-$.}
Elements X and Y belong to Group 15. The difference between the electronegativity values of 'X' and phosphorus is higher than that of the difference between phosphorus and 'Y'. 'X' & 'Y' are respectively

It is noticed that $Pb^{2+}$ is more stable than $Pb^{4+}$ but $Sn^{2+}$ is less stable than $Sn^{4+}$. Observe the following reactions. 
$PbO_2 + Pb \to 2PbO ; \Delta_rG^\circ(1)$ 
$SnO_2 + Sn \to 2SnO ; \Delta_rG^\circ(2)$ 
Identify the correct set from the following

$X_2(g) + Y_2(g) \rightleftharpoons 2Z(g)$. Equilibrium moles of $X_2, Y_2, Z$ are 3, 3, 9 mol (in 1 L). 10 mol of Z(g) is added. New equilibrium moles of Z(g) is ___. (Nearest integer)
Given below are two statements:
Statement I: $CH_3)_3C^+$ is more stable than $CH_3CH_2^+$ as nine hyperconjugation interactions are possible in $(CH_3)_3C^+$.
Statement II: $CH_3^+$ is less stable than $(CH_3)_3C^+$ as only three hyperconjugation interactions are possible in $CH_3^+$.
In the light of the above statements, choose the correct answer...
Which statements are NOT TRUE about $XeO_2F_2$?
A. It has a see-saw shape.
B. Xe has 5 electron pairs in its valence shell in $XeO_2F_2$.
C. The O-Xe-O bond angle is close to $180^\circ$.
D. The F-Xe-F bond angle is close to $180^\circ$.
E. Xe has 16 valence electrons in $XeO_2F_2$.


Consider the above electrochemical cell where a metal electrode (M) is undergoing redox reaction by forming $M^+$ ($M \to M^+ + e^-$). The cation $M^+$ is present in two different concentrations $c_1$ and $c_2$ as shown above. Which of the following statement is correct for generating a positive cell potential?

Identify the CORRECT set of details from the following: 
A. \([\text{Co}(\text{NH}_3)_6]^{3+}\): Inner orbital complex; \(d^2sp^3\) hybridized 
B. $[\text{MnCl}_6]^{3-}$: Outer orbital complex; $sp^3d^2$ hybridized 
C. $[\text{CoF}_6]^{3-}$: Outer orbital complex; $d^2sp^3$ hybridized 
D. $[\text{FeF}_6]^{3-}$: Outer orbital complex; $sp^3d^2$ hybridized 
E. $[\text{Ni}(\text{CN})_4]^{2-}$: Inner orbital complex; $sp^3$ hybridized}

In Carius method 0.2425 g of an organic compound gave 0.5253 g silver chloride. The percentage of chlorine in the organic compound is

Given below are two statements:
Statement I: Aniline can be synthesized from using simpler reagents in the order 
i) Acidic KMnO4,
ii) Ammonia,
iii) Bromine and alkali
Statement II: Aniline can be converted into using reagents in the order
i) Bromine-H2O
ii) NaNO2/HCl (0 - 5 C)
(iii) H3PO2. 
In the light of the above statements, choose the correct answer from the options given below:

Two liquids A and B form an ideal solution. At 320 K, the vapour pressure of the solution, containing 3 mol of A and 1 mol of B is 500 mm Hg. At the same temperature, if 1 mol of A is further added... vapour pressure of B in pure state is ___ mm Hg. (Nearest integer)
Total number of unpaired electrons present in the central metal atoms/ions of \([Ni(CO)_4]\), \([NiCl_4]^{2-}\), \([PtCl_2(NH_3)_2]\), \([Ni(CN)_4]^{2-}\) and \([Pt(CN)_4]^{2-}\) is
The work functions of two metals ($M_A$ and $M_B$) are in the 1 : 2 ratio. When these metals are exposed to photons of energy 6 eV, the kinetic energy of liberated electrons of $M_A$ : $M_B$ is in the ratio of 2.642 : 1. The work functions (in eV) of $M_A$ and $M_B$ are respectively.

Iodoform test can differentiate between

A. Methanol and Ethanol
B. CH\(_3\)COOH and CH\(_3\)CH\(_2\)COOH
C. Cyclohexene and cyclohexanone
D. Diethyl ether and pentan-3-one
E. Anisole and acetone

Choose the correct answer from the options given below:

Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of ___
'x' is the product from propenenitrile + $SnCl_2/HCl$ followed by hydrolysis. 'y' is the product from but-2-ene by ozonolysis. Which product is not obtained when 'x' and 'y' react in alkali with heating?
Consider the general reaction given below at 400 K: xA(g) ⇌ yB(g). The values of K___p and K___c are studied under the same condition of temperature but variation in x and y.
(i) K___p = 85.87 and K___c = 2.586
(ii) K___p = 0.862 and K___c = 28.62.
The values of x and y in (i) and (ii) respectively are :
Given, (A) n=5, m___l = -1; (B) n=3, l=2, m___l = -1, m___s = +1/2. The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are :

But-2-yne and hydrogen (one mole each) are separately treated with (i) Pd/C and (ii) Na/liq.NH₃ to give the products X and Y respectively.

Identify the incorrect statements.
A. X and Y are stereoisomers.
B. Dipole moment of X is zero.
C. Boiling point of X is higher than Y.
D. X and Y react with O₃/Zn + H₂O to give different products.
Choose the correct answer from the options given below :

Given below are two statements :
Statement I: Sublimation is used for the separation and purification of compounds with low melting point.
Statement II: The boiling point of a liquid increases as the external pressure is reduced.
In the light of the above statements, choose the correct answer from the options given below :

Compound 'P' undergoes the following sequence of reactions : (i) NH₃ (ii) $\Delta$ $\rightarrow$ Q (i) KOH, Br₂ (ii) CHCl₃, KOH (alc), $\Delta$ $\rightarrow$ NC-CH₃. 'P' is : 

Identify the molecule (X) with maximum number of lone pairs of electrons (obtained using Lewis dot structure) among HNO₃, H₂SO₄, NF₃, and O₃. Choose the correct bond angle made by the central atom of the molecule (X).
In two separate Young's double-slit experimental set-ups and two monochromatic light sources of different wavelengths are used to get fringes of equal width. The ratios of the slits separations and that of the wavelengths of light used are 2:1 and 1:2 respectively. The corresponding ratio of the distances between the slits and the respective screens (D₁/D₂) is_______.}
Which of the following statements regarding the energy of the stationary state is true in the following one-electron systems ?