List of top Chemistry Questions

Molar mass of the hydrocarbon (X) which on ozonolysis consumes one mole of O3 per mole of (X) and gives one mole each of ethanal and propanone is _______ g mol-1  
(Molar mass of C : 12 g mol-1 , H : 1 g mol-1)

Number of crystal systems from the following where body centred unit cell can be found, is......
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic.

The number of species having a square planar shape from the following is __
\(XeF_4, SF_4, SiF_4, BF^-_4 BrF^-_4,[Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [PtCl_4]^{2-}\)

Consider the following date
Heat of combustion of H₂(g)           = -241.8 kJ mol^-1 
Heat of combustion of C(s)              = -393.5 kJ mol^-1 
Heat of combustion of C₂H₅OH(1)  = -1234.7 kJ mol^-1
The heat of formation of C₂H₅OH(1) is (-) ____ kJ mol^-1 (Nearest integer)

Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solutions is/are...... 
A. 1 M aq. NaCl and 2 M aq. Urea 
B. 1 M aq. CaCl₂ and 1.5 M aq. KCl 
C. 1.5 M aq. AlCl₃ and 2 M aq. Na₂SO₄ 
D. 2.5 M aq. KCl and 1 M aq. Al₂(SO₄)₃

The equilibrium composition for the reaction PCl₃ + Cl₂ ⇌ PCI5, at 298 K is given below. 
[PCl₃]_eq = 0.2 mol L^-
[Cl₂]eq = 0.1 mol L^-1,
[PCl₅]_eq = 0.40 mol L^-1 
If 0.2 mol of Cl₂ is added at the same temperature, the equilibrium concentrations of PCl5 is ___ × 10^-2 mol L^-1
Given: K_c for the reaction at 298 K is 20

The standard reduction potential at 298 K for the following half cells are given below  
NO − 3 3 − + 4H+ + 3e- → NO(g) +2H2O E0 = 0.97V 
\(V^{2+} (aq) + 2e^-→V\)           E⁰ = -1.19V 
\(Fe^{3+}(aq) + 3e^- → Fe\)        E⁰ = -0.04V 
\(Ag^+ (aq) + e^- → Ag(s)\)      E⁰ = 0.80V 
\(Au^{3+}(aq)+3e^-→Au(s)\) E⁰ = 1.40V 
The number of metal(s) which will be oxidized by  \(N0^-_3\) Oin aqueous solution is______.

The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is____.
Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather.

In an ice crystal, each water molecule is hydrogen bonded to ___ neighbouring molecules

Among the following, the number of compounds which will give positive iodoform reaction is ____ .
(a) 1-Phenylbutan-2-one 
(b) 2-Methylbutan-2-ol 
(c) 3-Methylbutan-2-ol 
(d) 1-Phenylethanol 
(e) 3,3-dimethylbutan-2-one 
(f) 1-Phenylpropan-2-ol

Number of isomeric aromatic amines with synthesized by Gabriel Phthalimide synthesis molecular formula C₈H₁₁N, which can be is ______. jee main 2023

KMnO₄ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute H₂SO₄. Number of water molecules produced for 2 molecules of KMnO₄ is______.

A certain quantity of real gas occupies a volume of 30.15 dm3 at 100 atm and 500 K when its compressibility factor is 1.07. Its volume at 300 atm and 300K (When its compressibility factor is 1.4) is _____ x 10-4 dm3 (Nearest integer)

A₂+B₂→2AB. \(ΔH^0_f\)= -200 kJ mol^-1 AB, A2 and B2 are diatomic molecule. If the bond enthalpies of A₂, B₂ and AB are in the ratio 1:0.5:1, then the bond enthalpy of A₂ is ___ kJmol^-1 (Nearest integer)

Solution of 12 g of non-electrolyte (A) prepared by dissolving it in 1000 mL of water exerts the same osmotic pressure as that of 0.05 M glucose solution at the same temperature. The empirical formula of A is CH₂O. The molecular mass of A is ____ g. (Nearest integer)

25.0 mL of 0.050 M Ba(NO₃)₂ is mixed with 25.0 mL of 0.020 M NaF. K_sp of BaF₂ is 0.5 x 10^-6 at 298 K. The ratio of [Ba2+] [F^-]² and K_sp is__ (Nearest integer)

A metal surface of 100 cm2 area has to be coated with nickel layer of thickness 0.001mm. A current of 2A was passed through a solution of Ni (NO₃)₂ for 'x' seconds to coat the desired layer. The value of x is_____ (Nearest integer)
 (P_Ni (density of Nickel) is 10 gmL^-1, Molar mass of Nickel is 60 gmol^-1 F = 96500 C mol^-1)

For the given reaction

The total number of possible products formed by tertiary carbocation of A is____.

20 mL of calcium hydroxide was consumed when it was reacted with 10 mL of unknown solution of H₂SO4. Also 20 mL standard solution of 0.5 M HCI containing 2 drops of phenolphthalein was titrated with calcium hydroxide the mixture showed pink colour when burette displayed the value of 35.5 mL whereas the burette showed 25.5 mL initially. The concentration of H₂SO₄ is_____M (Nearest integer)

Consider the graph of Gibbs free energy G vs Extent of reaction. The number of statement/s from the following which are true with respect to points (a), (b) and (c) is…

A. Reaction is spontaneous at (a) and (b)  
B. Reaction is at equilibrium at point (b) and nonspontaneous at point (c)  
C. Reaction is spontaneous at (a) and nonspontaneous at (c)  
D. Reaction is non-spontaneous at (a) and (b)

For the adsorption of hydrogen on platinum, the activation energy is 30 kJ mol^-1 and for the adsorption of hydrogen on nickel, the activation energy is 41.4 kJ mol^-1 . The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at 300 K is ……… (Nearest integer) Given: ln 10 = 2. 3  R = 8.3 JK^-1 mol^-1

At 600K, the root mean square (rms) speed of gas X (molar mass = 40) is equal to the most probable speed of gas Y at 90K. The molar mass of the gas Y is ____ g mol^-1. (Nearest integer)

One mole of an ideal gas at 350K is in a 2.0 L vessel of thermally conducting walls, which are in contact with the surroundings. It undergoes isothermal reversible expansion from 2.0L to 3.0L against a constant pressure of 4 atm. The change in entropy of the surroundings (ΔS) is JK (Nearest integer) Given: R = 8.314 J K^-1 Mol^-1.

80 mole percent of MgCl₂ is dissociated in aqueous solution. The vapour pressure of 1.0 molal aqueous solution of M_gCl₂ at 38°C is ____mm Hg. (Nearest integer)
Given : Vapour pressure of water at 38°C is 50 mm Hg.

The reaction 2NO + Br2 → 2NOBr 
takes places through the mechanism given below : 
NO + Br2 ⇔ NOBr2 (fast)  
NOBr2 + NO → 2NOBr (slow) 
The overall order of the reaction is_____.