List of top Chemistry Questions

Which of the following will have a spin-only magnetic moment of 2.86 BM?
Which of the following statements is correct regarding boric acid?

Arrange the following in the correct order of their boiling points: 

What is the major product Z in the given reaction sequence?

Assertion (A): Silicones are used for waterproofing of fabrics. 
Reason (R): The repeating unit in silicones is 

Adsorption of a gas on a solid adsorbent follows the Freundlich adsorption isotherm. If \(x\) is the mass of the gas adsorbed on mass \(m\) of the adsorbent at pressure \(p\), and from the graph of \(\log\left(\frac{x}{m}\right)\) vs. \(\log p\) we obtain a slope of \(\tfrac{1}{2}\), then the extent of adsorption is proportional to: 

Identify the correct statements about Z: 

I. \(Z\) is an aldehyde. 
II. \(Z\) undergoes Cannizzaro reaction. 
III. \(Z\) gives iodoform test. 
IV. \(Z\) does not give a test with Tollen's reagent.

If the degree of dissociation of formic acid is 11.0\%, what is the molar conductivity of its 0.02 M solution? \[ \text{Given: } \Lambda^\infty (\mathrm{H}^+) = 349.6 \, \text{S cm}^2 \text{mol}^{-1}, \quad \Lambda^\infty (\mathrm{HCOO}^-) = 54.6 \, \text{S cm}^2 \text{mol}^{-1}. \]
Consider the gaseous reaction: \[ \text{A}_2 + \text{B}_2 \;\longrightarrow\; 2\,\text{AB} \] The following initial-rate data were obtained for the above reaction (rate of formation of AB): \includegraphics[]{144.png} The value of the rate constant for the above reaction is:
Assertion (A): Aldehydes are more reactive than ketones towards nucleophilic addition reactions.
Reason (R): In aldehydes, the carbonyl carbon is less electrophilic compared to ketones.
A message signal of peak voltage 12 V is used to amplitude modulate a carrier signal of frequency 1.2 MHz. The amplitude of the side bands is:
Consider the following reactions: \[ \text{Cs} + O_2 (\text{excess}) \rightarrow X \] \[ \text{Cs} + O_2 (\text{limited}) \rightarrow X \] \[ \text{Na} + O_2 \rightarrow Y \] Identify the correct statement about \( X \) and \( Y \).
The kinetic energy of electrons emitted, when radiation of frequency \( 1.0 \times 10^{15} \) Hz hits a metal, is \( 2 \times 10^{-19} \) J. What is the threshold frequency of the metal (in Hz)? (\( h = 6.6 \times 10^{-34} \) Js)
Consider the following reactions: \[ X + \text{O}_2 \;\longrightarrow\; \text{Cu}_2\text{O} + \text{SO}_2 \] \[ \text{Cu}_2\text{O} + 2\,\text{H}_2 \;\longrightarrow\; 2\,\text{Cu} + \text{H}_2\text{O} \] If the molecule \(Y\) is formed in the first reaction, the shape of molecule \(Y\) is:

Arrange the following in the increasing order of pKa values. 

Identify the correct statement about the crystal defects in solids:
The molar conductivity of 0.02 M solution of an electrolyte is \( 124 \times 10^{-4} \) S m\(^{2}\) mol\(^{-1}\). What is the resistance of the same solution (in ohms), kept in a cell of cell constant 129 m\(^{-1}\)?
An element with molar mass \( 2.7 \times 10^{-2} \) kg mol\(^{-1}\) forms a cubic unit cell with an edge length of 405 pm. If its density is \( 2.7 \times 10^3 \) kg m\(^{-3}\), the number of atoms present in one unit cell is: (Given: \( N_A = 6.023 \times 10^{23} \) mol\(^{-1}\))
The decomposition of benzene diazonium chloride is a first-order reaction. The time taken for its decomposition to \( \frac{1}{4} \) and \( \frac{1}{10} \) of its initial concentration are \( t_{1/4} \) and \( t_{1/10} \) respectively. The value of \( \frac{t_{1/4}}{t_{1/10}} \times 100 \) is: (Given: log 2 = 0.3)
At 300 K, 0.06 kg of an organic solute is dissolved in 1 kg of water. The vapour pressure of the solution is 3.768 kPa. If the vapour pressure of pure water at that temperature is 3.78 kPa, what is the molar mass of the solute (in g mol\(^{-1}\))?
Cheilosis disease and digestive disorders are caused by the deficiency of:

What is the total number of sigma bonds found in the following compound?
\[ \text{CH}_3\text{CH} = \text{C} = \text{CH} - \text{C} \equiv \text{C} - \text{H} \]

Which of the following carboxylic acids has the highest pKa?
 

Which of the following base is not present in RNA molecule?
Which is the incorrect statement with regard to 1-phenylethanol?