List of top Chemistry Questions

A carbonyl compound X(C$_5$H$_8$O) gives yellow precipitate with NaOI. Hemiacetal of X with methanol/dry HCl is:
In the following sequence of reactions, what is the end product (D)?
C$_2$H$_5$Br $\xrightarrow{\text{KCN}}$ A $\xrightarrow{\text{H$_3$O$^+$}}$ B $\xrightarrow{\text{LiAlH$_4$}}$ C $\xrightarrow{\text{Cu, 573 K}}$ D
What are X and Y respectively, in the given set of reactions?
CH3CH2CH2Cl
The structure of the nitrogen-containing heterocyclic base shown below represents:
Which of the following does not involve in Friedel-Crafts reaction?

Match the following:

List-I (Aquated ion)List-II (Colour)
A) Ni\(^{2+}\)V) Green
B) Fe\(^{3+}\)III) Yellow
C) Mn\(^{3+}\)I) Violet
D) V\(^{4+}\)II) Blue
The ion with 4f$^7$ configuration is:
Which of the following sets are correctly matched?
I) Hg — distillation
II) Cu — poling
III) B — zone refining
IV) Ti — liquation
Consider the following.
Statement-I: Gold sol is prepared by Bredig’s arc method.
Statement-II: Bredig’s arc method involves only dispersion but not condensation.
Which of the following is the common monomer for the polymers Bakelite and Melamine?
The oxides of nitrogen obtained by the reaction of nitric acid with
At 300 K, vapour pressure of pure liquid A is 70 mm Hg. It forms an ideal solution with liquid B. Mole fraction of B = 0.2 and total vapour pressure of solution = 84 mm Hg. What is vapour pressure (in mm) of pure B?
A centi molar solution of acetic acid is 50% dissociated at 27$^\circ$C. The osmotic pressure of the solution (in atm) is (R = 0.083 L atm K$^{-1}$ mol$^{-1}$)
Identify the catalytic reaction in which both reactants are in different phases.
The catalyst used for the isomerisation of n-alkanes to branched chain alkanes is:
An element crystallizes in bcc lattice. The atomic radius of the element is 2.598 \AA. What is the volume (in cm$^3$) of one unit cell?
In the structure of diborane, the number of 2-centre-2-electron bonds is X and 3-centre-2-electron bonds is Y. The value of (X + Y) is:
Which of the following orders are correct against the stated property?
I) NaO$_2 < KO$_2 < RbO$_2 < CsO$_2$ — stability
II) Mg(OH)$_2 < Ca(OH)$_2 < Sr(OH)$_2$ — basic strength
III) MgCO$_3 < CaCO$_3 < SrCO$_3$ — thermal stability

Match the following:

List-I (Compound)List-II (Use)
A) KieselguhrIV) To convert alcohol directly into gasoline
B) Silica gelI) Chromatographic material
C) ZSM-5III) Filtration plants
D) Hydrated zeolitesII) Softening of hard water
$H_2O_2$ with $KMnO_4$ in acidic medium gives a manganese compound 'X' and in basic medium gives another manganese compound 'Y'. The oxidation states of manganese in X and Y respectively are:
Identify the air pollutant which in high concentration leads to stiffness of flower buds?
At 25$^\circ$C, the percentage of ionization of x M acetic acid is 4.242. What is the pH of the acetic acid solution?
Given: $\log 4.242 = 0.6275$, $\log 0.04242 = -1.372$, $K_a = 1.8 \times 10^{-5}$
209 g of an element reacts with chlorine to form 315.5 g of its chloride. What is the weight of oxygen that reacts with 418 g of the same element? (Cl = 35.5, O = 16)
Consider the following
Statement-I: During isothermal expansion of an ideal gas its enthalpy decreases.
Statement-II: When 2.0 L of an ideal gas expands isothermally into vacuum, $\Delta U = 0$.
The uncertainty in the position of electron ($\Delta x$) is approximately 100 pm. The uncertainty in momentum (in kg m s$^{-1}$) of an electron is [h = 6.626 $\times 10^{-34}$ Js]