List of top Chemistry Questions on Dual nature of radiation and matter

Which of the allotropic forms of carbon is aromatic in nature?
If \( \lambda_0 \) and \( \lambda \) are respectively the threshold wavelength and wavelength of incident light, the velocity of photoelectrons ejected from the metal surface is:

What are X and Y respectively in the following reactions? 


 

Two statements are given below:
I. Shaving soaps contain sodium carbonate
II. Laundry soaps contain sodium rosinates
The correct answer is:

The probability density plots of 1s and 2s orbitals are given in figure. 

 

The density of dots in a region represents the probability density of finding electrons in the region. On the basis of the above diagram, which of the following statements is incorrect?

How much ethyl alcohol must be added to 1 litre of water so that the solution will freeze at \(-14^\circ \text{C}\)? 

(Kf for water = 1.86 °C/mol)

If enthalpies of formation of \( {C}_2{H}_4(g) \), \( {CO}_2(g) \) and \( {H}_2{O}(l) \) at 25°C and 1 atm pressure are 52, 394 and -286 kJ/mol respectively, the change in enthalpy for combustion of \( {C}_2{H}_4 \) is equal to:
Which of the following will precipitate first when an aqueous solution containing sulphate ions is added?

Among the given halides, which one will give the same product in both S\(_N1\) and S\(_N2\) reactions? 

A monochromatic radiation is incident on a solution of 0.05 molar concentration of an absorbing substance. The intensity of the radiation is reduced to one fourth of the initial value after passing through 10 cm length of the solution. Calculate the molar extinction. coefficient of the substance.
Identify the infrared active molecules from the following
A. N2
B. NO
C. CO
D. CO2
Choose the correct answer from the options given below:
The energy of one mole of photons of radiation of wavelength \(300\) \(nm\) is (Given \(h\) = \(6.63 × 10^{–34}\)Js, \(N_A\) = \(6.02 × 10^{23}\) \(mol^{–1}\), \(c = 3 × 10^8\) \(ms^{–1}\))
The energies \( E_1 \) and \( E_2 \) of two radiations are 25 eV and 50 eV, respectively. The relation between their wavelengths i.e., \( \lambda_1 \) and \( \lambda_2 \), will be:
Wave nature of electromagnetic radiation is observed in
The activity of ratio altitude $ ({{X}^{100}}) $ is 6.023 curie. If its disintegration constant is $ 3.7\times {{10}^{4}}{{\sec }^{-1}}, $ the mass of X is :
If the kinetic energy of the particle is increased to $16$ times its previous value, the percentage change in the de Broglie wavelength of the particle is
The wavelength of a 1 keV photon is 1.24 nm. The frequency of 1 MeV photon is:
Which one of the following observations is not true when a mixture of KCl, K2Cr2O7 and conc. H2SO4 is warmed carefully?
Consider the following statements:
Statement I: The number of emitted photoelectrons Increases with increase in frequency of incident light.
Statement II: Kinetic energy of emitted photoelectrons increases with increase in frequency of incident light
In a photoelectric experiment, if both the intensity and frequency of the incident light are doubled, then the saturation photoelectric current