List of top Chemistry Questions

A molecule has a T-shape. The total number of electron pairs in the valence shell of its central atom is:
Arrange the products I, II, III from the following reactions in decreasing order of their acid strength.
Arrange the products I, II, III

The final product (C) in the given reaction sequence is

Match the following pollutant concentration limits in water with their effects:
List-I (Pollutant Concentration Limit in Water)List-II (Effect)
Pollutant 1Effect 1
Pollutant 2Effect 2
Pollutant 3Effect 3
Pollutant 4Effect 4

Match the following:
List-I (Glycosidic linkage) 
A. $\alpha$-1,4 
B. $\beta$-1,4 
C. $\alpha$-1,4, $\alpha$-1,6 
List-II (Polysaccharide) 
I. Amylose 
II. Amylopectin 
III. Cellulose

At 25 \(^{\circ}\)C, \( K_a \) of acetic acid is \( 1.8 \times 10^{-5} \). What is the percentage of ionization of 0.02 M acetic acid at this temperature?
At \( T \)(K), hydrogen and oxygen gases are mixed in the ratio of \( 1:2 \) by mass in a closed vessel of volume \( V \) litres. If the total pressure of the gaseous mixture is \( p \) atm, the partial pressure of oxygen (in atm) is:
Identify the correct statements regarding the enzymes
I) Almost all enzymes are proteins
II) Enzymes are not specific in nature
III) Enzymes work effectively in the pH range of 5–7
IV) Enzymes work effectively between 310 K and 330 K temperature
Which set of elements form electron-precise hydrides?
Gas X is obtained in Deacon's process. X on reacting with iodine and water gives:
Consider the following reaction A(g) + 3B(g) \( \longrightarrow \) 2C(g); \( \Delta H^\ominus = -24 \) kJ. At \(25 \, ^\circ\text{C}\) if \( \Delta G^\ominus \) of the reaction is -9 kJ, the standard entropy change (in JK\(^{-1}\)) of the same reaction at same temperature is
Consider the following statements:
Statement-I: Lysine, arginine are essential and basic amino acids.
Statement-II: Leucine, phenyl alanine are non-essential and neutral amino acids.
Which of the following is correct?
At 298 K, the value of K\(_p\) for N\(_2\)O\(_4\)(g) \(\rightleftharpoons\) 2NO\(_2\)(g) is 0.113 atm. The partial pressure of N\(_2\)O\(_4\) at equilibrium is 0.2 atm. What is the partial pressure (in atm) of NO\(_2\) at equilibrium ?
Match the following
List-I (Symbol of electrical property)List-II (Units)
A) \( \Omega \)I) S cm\(^{-1}\)
B) GII) m\(^{-1}\)
C) \( \kappa \)III) S cm\(^2\) mol\(^{-1}\)
D) G\(^*\)IV) S
The following equation is obtained for a first order reaction at 300 K.
$\log_{10} \frac{k}{A} = 0.00174$ What is the activation energy (in J mol\(^{-1}\)) of the reaction ?
(R = 8.314 J mol\(^{-1}\) K\(^{-1}\))
Among the following compounds, which one is not responsible for the depletion of ozone layer?
One mole of \( \text{C}_2\text{H}_5\text{OH(l)} \) was completely burnt in oxygen to form \( \text{CO}_2\text{(g)} \) and \( \text{H}_2\text{O(l)} \). The standard enthalpy of formation (\( \Delta_f H^\ominus \)) of \( \text{C}_2\text{H}_5\text{OH(l)} \), \( \text{CO}_2\text{(g)} \) and \( \text{H}_2\text{O(l)} \) is x, y, z kJ mol\(^{-1}\) respectively. What is \( \Delta_r H^\ominus \) (in kJ mol\(^{-1}\)) for this reaction?
The sum of number of antibonding electrons present in O$_2$, O$_2^+$, O$_2^-$ is:

Which of the following represents the wavelength of spectral line of Balmer series of He$^+$ ion? (R = Rydberg constant, n $>$ 2)

White phosphorus on heating with concentrated NaOH solution in an inert atmosphere of CO\(_2\) gives a salt 'X' and gas 'Y'. The oxidation state of central atom in X and Y is respectively
What is ‘Y’ in the following reaction sequence?
Y’ in the following reaction sequence
Which of the following sets is correctly matched?
The incorrect statement from the following is
Observe the following molecules: ClF, SF$_4$, CH$_4$, NH$_3$, XeF$_4$, PCl$_5$. The number of molecules in which the central atom has expanded octet is:
The standard enthalpy of formation of C\(_2\)H\(_4\)(g), CO\(_2\)(g), and H\(_2\)O(l) are 52, –394, and –286 kJ mol\(^{-1}\) respectively. The heat evolved by burning 7 g of C\(_2\)H\(_4\)(g) is