List of top Chemistry Questions

When a manganous salt is fused with a mixture of $KNO_3$ and solid $NaOH$ the oxidation number of $Mn$ changes from $+2$ to

In hemoglobin the metal ion present is

Compound formed by electrolysis of a mixture of ethanol and NaCl is

A solution of sucrose (molar mass = $342 \,g \,mol^{-1}$) has been prepared by dissolving $68.5 \,g$ of sucrose in $1000 \,g$ of water. The freezing point of the solution obtained will be ($K_f$ for water = $1.86 \, K \, kg \, mol^{-1}$)

$AB$ crystallizes in a body centred cubic lattice with edge length 'a' equal to $387 \,pm$. The distance between two oppositely charged ions in the lattices is

Which of the following does not exihibit the phenomena of mutarotation?

Some of the properties of the two species, $NO_3^-$ and ${H_3O^+}$ are described below. Which one of them is correct?

In the following reaction sequence, $ \ce{CH3CHO ->[Cl_2][Ca(OH)_2] X ->[C_6H_5NH_2][Alc. KOH] Y}$ $Y$ is

$0.023\, g$ of sodium metal is reacted with $100 \,cm^3$ of water. The pH of the resulting solution is ______

A white crystalline salt $A$ reacts with dilute $HCl$ to liberate a suffocating gas $B$ and also forms a yellow precipitate. The gas $B$ turns potassium dichromate acidified with dilute $H_2SO_4$ to a green coloured solution $C, A, B$ and $C$ are respectively

Oxidation states of $P$ in $ H_4 \, P_2 \, O_5, H_4, P_2, O_6 , H_4 P_2 O_7 $ respectively are

The rate of the reaction $ {2NO + Cl_2 -> 2NOCl}$ is given by the rate equation rate = $ { k[NO]^2[Cl_2]}$ . The value of the rate constant can be increased by -

Which one of the following does not involve coagulation?

$ N_{2} $ gas will not be evolved upon reaction of $ HNO_3$ with which of the following amines?

In a buffer solution containing equal concentration of $ B^- $ and HB, the $ K_b $ for $ B^- $ is $ 10^{-10} $ . The pH of buffer solution is

What is $ [H^+] $ in mol/L of a solution that is $0.20 \,M$ in $ CH_3COONa $ and $0.10 \,M$ in $ CH_3COOH $ ? $ (K_a\, \, for\, \, CH_3COOH = 1.8 \times 10^{-5}) $

A mixture of $CaCl_2$ and $NaCl$ weighing $4.44\, g$ is treated with sodium carbonate solution to precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get $0.56\, g$ of $CaO$. The percentage of $NaCl$ in the mixture is (Atomic mass of $Ca = 40)$

In Kjeldahl's method, ammonia from $5\, g$ of food neutralizes $30 \,cm^3$ of $0.1\, N$ acid. The percentage of nitrogen in the food is

In the electrolytic refining of Zinc ,.................

: One molar aqueous solution has always higher concentration than one molal. : The molality of a solution depends upon the density of the solution whereas molarity does not.

The species which by definition has zero standard molar enthalpy of formation at $298 \,K$ is

Among the following, intensive property is (properties are)

Which one of the following species does not exist under normal conditions?

The packing efficiency of the two-dimensional square unit cell shown below is

In alkaline medium, glycine exists predominantly as