List of top Chemistry Questions

During estimation of Nitrogen by Dumas' method of compound X (0.42 g) :
 
mL of $ N_2 $ gas will be liberated at STP. (nearest integer) $\text{(Given molar mass in g mol}^{-1}\text{ : C : 12, H : 1, N : 14})$

The formation enthalpies, \( \Delta H_f^\circ \) for \( \text{H}_2 \) and \( \text{O}_2 \) are 220.0 and 250.0 kJ mol\(^{-1}\), respectively, at 298.15 K, and \( \Delta H_f^\circ \) for \( \text{H}_2\text{O} \) (g) is -242.0 kJ mol\(^{-1}\) at the same temperature. The average bond enthalpy of the O-H bond in water at 298.15 K is: 
Which of the following compounds exhibits ionic bonding?
Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12. The current in Amperes used for the given electrolysis is ________________________. (Nearest integer).
Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is:
When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if the decrease in vapour pressure is 20 mm of Hg?
Consider the equilibrium: \[ \text{CO(g)} + \text{3H}_2\text{(g)} \rightleftharpoons \text{CH}_4\text{(g)} + \text{H}_2\text{O(g)} \] If the pressure applied over the system increases by two fold at constant temperature then:
2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is: (Given: Ebullioscopic constant of water = $ 0.52 \, \text{K kg mol}^{-1} $)

Match List-I with List-II

Choose the correct answer from the options given below :

The product B formed in the following reaction sequence is: $$ {C}_6{H}_5{CN} \xrightarrow{{HCl}} (A) \xrightarrow{{AgCN}} (B) $$  
Total number of non-bonded electrons present in \( \text{NO}_2 \); ion based on Lewis theory is:
Consider the following elements In, Tl, Al, Pb, and Ge. The most stable oxidation states of elements with highest and lowest first ionisation enthalpies, respectively, are:

The correct stability order of the following species/molecules is:
 


 

Which of the following is/are correct with respect to the energy of atomic orbitals of a hydrogen atom? 
(A) \( 1s<2s<2p<3d<4s \) 
(B) \( 1s<2s = 2p<3s = 3p \) 
(C) \( 1s<2s<2p<3s<3p \) 
(D) \( 1s<2s<4s<3d \) 
Choose the correct answer from the options given below:

Given below are two statements: 
Statement I: A homoleptic octahedral complex, formed using monodentate ligands, will not show stereoisomerism 
Statement II: cis- and trans-platin are heteroleptic complexes of Pd. 
In the light of the above statements, choose the correct answer from the options given below

Find the dimensions of \( \frac{B}{\mu_0} \)
Atomic number of element with lowest first ionisation enthalpy is:

The descending order of basicity of following amines is :

Choose the correct answer from the options given below :

$\mathrm{KMnO}_{4}$ acts as an oxidising agent in acidic medium. ' X ' is the difference between the oxidation states of Mn in reactant and product. ' Y ' is the number of ' d ' electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of $\mathrm{X}+\mathrm{Y}$ is _______ .

The molar solubility(s) of zirconium phosphate with molecular formula \( \text{Zr}^{4+} \text{PO}_4^{3-} \) is given by relation:
The percentage dissociation of a salt (MX$_3$) solution at a given temperature (van't Hoff factor $i = 2$) is .................. % (Nearest integer)

Given below are two statements: 
Statement I : The N-N single bond is weaker and longer than that of P-P single bond 
Statement II : Compounds of group 15 elements in +3 oxidation states readily undergo disproportionation reactions. 
In the light of above statements, choose the correct answer from the options given below

In the following series of reactions identify the major products A and B respectively.

Match the Compounds (List- I) with the appropriate Catalyst/Reagents (List- II) for their reduction into corresponding amines.
Match the Compounds (List- I) with the appropriate Catalyst/Reagents (List- II) for their reduction into corresponding amines.

Consider the following reaction:

\[ A + NaCl + H_2SO_4 \xrightarrow[\text{Little amount}]{} CrO_2Cl_2 + \text{Side products} \] \[ CrO_2Cl_2(\text{Vapour}) + NaOH \rightarrow B + NaCl + H_2O \] \[ B + H^+ \rightarrow C + H_2O \]

The number of terminal 'O' present in the compound 'C' is ________.