List of top Chemistry Questions

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?
At temperature T, compound AB2 dissociates as \( AB_2 \rightleftharpoons A + \frac{1}{2} B_2 \), having degree of dissociation \( x \) (small compared to unity). The correct expression for \( x \) in terms of \( K_p \) and \( p \) is:

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) $\text{(Given molar mass in g mol}^{-1}\text{ : C : 12, H : 1, N : 14})$

Match List - I with List - II.

Partial Derivatives Thermodynamic Quantity

Choose the correct answer from the options given below :

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:
The heat of formation of \( \text{SO}_2(g) \) is given by: \[ S(g) + \frac{3}{2} O_2(g) \rightarrow SO_3(g) + 2x \, \text{kcal} \] \[ SO_2(g) + \frac{1}{2} O_2(g) \rightarrow SO_3(g) + y \, \text{kcal} \]
The percentage dissociation of a salt (MX$_3$) solution at a given temperature (van't Hoff factor $i = 2$) is .................. % (Nearest integer)
Total number of non-bonded electrons present in \( \text{NO}_2 \); ion based on Lewis theory is:

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 ________.

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

Given below are two statements:
Statement (I): The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.
Statement (II): Melting points and boiling points of group 13 elements are in general much higher than those of the corresponding elements of group 14. Choose the most appropriate answer from the options given below:
Find the dimensions of \( \frac{B}{\mu_0} \)
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:

$\mathrm{KMnO}_{4}$ 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 _______ .

Given below are two statements: 
Statement (I): Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction. 
Statement (II): In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the $ \beta $-carbon. 
In the light of the above statements, choose the most appropriate answer from the options given below:

The molar solubility(s) of zirconium phosphate with molecular formula \( \text{Zr}^{4+} \text{PO}_4^{3-} \) is given by relation:
Given below are two statements:
Statement (I): In partition chromatography, the stationary phase is a thin film of liquid present in the inert support.
Statement (II): In paper chromatography, the material of paper acts as a stationary phase.
In light of the above statements, choose the correct answer from the options given below:
Given below are two statements:
Statement I: In Lassaigne's test, the covalent organic molecules are transformed into ionic compounds.
Statement II: The sodium fusion extract of an organic compound having N and S gives prussian blue colour with FeSO4 and Na4[Fe(CN)6].
In the light of the above statements, choose the correct answer from the options given below.

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 : 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

The product B formed in the following reaction sequence is: $$ {C}_6{H}_5{CN} \xrightarrow{{HCl}} (A) \xrightarrow{{AgCN}} (B) $$  

The descending order of basicity of following amines is :

Choose the correct answer from the options given below :

Atomic number of element with lowest first ionisation enthalpy is:

A(g) $ \rightarrow $ B(g) + C(g) is a first order reaction.

The reaction was started with reactant A only. Which of the following expression is correct for rate constant k ?