List of top Chemistry Questions

An alkene 'X' on ozonolysis gives a mixture of ethanal and pentan-3-one. The IUPAC name of alkene 'X' is

A solution is prepared by dissolving ethanol in water. The mole fraction of ethanol in this solution is 0.04. What is the molarity (in $\text{mol L}^{-1}$) of the solution? (density of water is $1\text{ g mL}^{-1}$. Neglect the volume of ethanol)

In the estimation of nitrogen by Kjeldahl's method, the ammonia evolved from 0.30 g of an organic compound (X) was passed into 100 mL of 0.1 M $\text{H}_2\text{SO}_4$. The unreacted acid required 20 mL of 0.5 M NaOH for complete neutralization. What is X?

Identify the correct option in which the compound is not named as per IUPAC
(A)

(B)

(C)

(D)

Given below are statements
Statement I: Unit cell in a lattice has six characteristic parameters
Statement II: In fcc lattice, the total number of atoms/ions per unit cell is 4

In group 14 elements, element X has lowest melting point. This on heating with steam gives a compound Y. What is Y?

Which of the following statements are not correct about compounds of Beryllium?
I. Beryllium halides are covalent in nature
II. $\text{Be(OH)}_2$ is basic in nature
III. $\text{BeCO}_3$ is unstable
IV. BeO has rock salt structure

The pH of 1 L of HCl solution is 1.0. What is the volume (in L) of water to be added to this solution to increase its pH to 2.0?

Aluminium carbide on reaction with heavy water gives a carbon compound X. The hybridization in X is

The nature of oxides of aluminium, boron and gallium are respectively

Given below are two statements:
Statement I: Physical equilibrium takes place only in closed systems at a given temperature
Statement II: For an equilibrium reaction, $\Delta_r G$ is zero

Consider the following reaction: \[ \text{CCl}_4(g) \rightarrow \text{C}(g) + 4 \text{Cl}(g) \quad \Delta H = 1304\text{ kJ} \] What is $\Delta_{\text{vap}} H^\ominus$ of $\text{CCl}_4(l)$ (in $\text{kJ}\cdot\text{mol}^{-1}$)?
Given: $\Delta_f H^\ominus(\text{CCl}_4(l)) = -135.5\text{ kJ}\cdot\text{mol}^{-1}$, $\Delta_a H^\ominus(\text{C}) = 715\text{ kJ}\cdot\text{mol}^{-1}$, $\Delta_a H^\ominus(\text{Cl}_2) = 242\text{ kJ}\cdot\text{mol}^{-1}$

Consider the following reaction: \[ \text{CaCO}_3(s) \rightarrow \text{CaO}(s) + \text{CO}_2(g) \quad \Delta H = 178\text{ kJ} \] The standard enthalpy of formation of $\text{CaCO}_3(s)$ and $\text{CO}_2(g)$ is $-1207$ and $-393\text{ kJ}\cdot\text{mol}^{-1}$ respectively. What is $\Delta_f H^\ominus$ (in $\text{kJ}\cdot\text{mol}^{-1}$) of $\text{CaO}(s)$?

3 g of $\text{O}_2$ diffuses from a container in 15 min. The mass (in g) of $\text{SO}_2$ diffusing from the same container under the same conditions is (At. wt: $\text{O} = 16$ u, $\text{S} = 32$ u)

Which of the following have same number of significant figures?
(A) 0.0025
(B) 0.0430
(C) 5005
(D) 500.0
(E) 2.003

Which of the following statements is correct?

In which of the following elements are correctly arranged in the increasing order of their electronegativity values?

Match the following:

The bond order of a homodiatomic molecule is 3. If the number of bonding electrons in it is 10, the number of antibonding electrons will be

In hydrogen spectrum, the frequency of the spectral line corresponding to electron transition $n_2 = 3$ to $n_1 = 2$ is $x$ Hz. What is the frequency (in Hz) of the spectral line corresponding to electron transition $n_2 = 4$ to $n_1 = 3$ of $\text{He}^+$ spectrum?

Which of the following electrolytic solutions of the same electrolyte has maximum electrolytic conductivity at the same temperature?

The reaction of lithium with water is less vigorous than that of sodium. It is due to \[ \begin{aligned} \text{I. }& \text{Most negative }E^\circ\text{ value of }\mathrm{Li^+/Li}\\ \text{II. }& \text{Small size of Li}\\ \text{III. }& \text{Very high hydration energy of }\mathrm{Li^+} \end{aligned} \] The correct answer is

Which of the following statements are correct about salts of oxoacids of group 2 elements? \[ \begin{aligned} \text{I. }& \text{Their carbonates are generally insoluble in water.}\\ \text{II. }& \text{Solubility of their sulphates in water decreases from } \mathrm{CaSO_4} \text{ to } \mathrm{BaSO_4}.\\ \text{III. }& \text{Their nitrates undergo decomposition on heating.} \end{aligned} \] The correct answer is