List of top Chemistry Questions

A pure substance M has lesser density in solid state than in liquid state. The $\Delta S_\text{fusion}$ of M is +25 J K$^{-1}$ mol$^{-1}$. The CORRECT representative Pressure–Temperature diagram for the fusion of M is 

Which of the following has highest mass ?
Why do ketones and carboxylic acids have higher boiling points as compared to aldehydes?
Find the final product for the reaction: \[ \text{C}_6\text{H}_5\text{CHO} + \text{CH}_3\text{CO}\text{C}_6\text{H}_5 \xrightarrow{\text{OH}^-, 293 K} \text{Product} \]

What is the product formed when benzene reacts with CO and HCl in presence of anhydrous AlCl\(_3\)? 
 

In the detection of II group acid radical, the salt containing chloride is treated with concentrated sulphuric acid, the colourless gas is liberated. The name of the gas is
Given below are two statements :
Statement I : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus.
Statement II : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number.
In the light of the above statements, choose the most appropriate answer from the options given below :

The major product of the following reaction is : 
(Image shows Benzene reacting with 2-nitropropene in presence of H$_2$SO$_4$) 

For the following sequence of reactions, the correct products are : 

Arrange the following conformational isomers of n-butane in order of their increasing potential energy : 
 

The major product of the following reaction is : 

The spin only magnetic moment of a divalent ion in aqueous solution (atomic number 29) is ________ BM.
Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization energy of metal A in kJ mol⁻¹ is ________ . (Rounded-off to the nearest integer) [h=6.63$\times$10⁻³⁴ Js, c=3.00$\times$10⁸ ms⁻¹, N$_A$=6.02$\times$10²³ mol⁻¹]
Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is ________ . (Integer answer)
(A) Li (B) Na (C) Rb (D) Cs
Consider titration of NaOH solution versus 1.25 M oxalic acid solution. At the end point following burette readings were obtained. (i) 4.5 mL, (ii) 4.5 mL, (iii) 4.4 mL, (iv) 4.4 mL, (v) 4.4 mL. If the volume of oxalic acid taken was 10.0 mL then the molarity of the NaOH solution is _______ M. (Rounded-off to the nearest integer)
The unit cell of copper corresponds to a face centered cube of edge length 3.596 Å with one copper atom at each lattice point. The calculated density of copper in kg/m³ is ________ . [Molar mass of Cu: 63.54 g; Avogadro Number=6.022$\times$10²³]
What is 'X' in the given reaction?
CH$_2$OH—CH$_2$OH + oxalic acid $\xrightarrow{210^\circ\text{C}}$ X (major product)
Given below are two statements:
Statement I: The pH of rain water is normally ~5.6.
Statement II: If the pH of rain water drops below 5.6, it is called acid rain.
Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?
Which one of the following statements is FALSE for hydrophilic sols?
The correct order of bond dissociation enthalpy is:
Given below are two statements:
Statement I: $\alpha$ and $\beta$ forms of sulphur can change reversibly between themselves with slow heating or slow cooling.
Statement II: At room temperature the stable crystalline form of sulphur is monoclinic sulphur.
The set of elements that are used in the fabrication of transistors is:
The method used for the purification of Indium is:
Water does not produce CO on reacting with: