List of top Chemistry Questions

Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is____.

Match List-I with List-II

List-I(Mixture)	List-II(Purification Process)
(A) Chloroform & Aniline	(I) Steam distillation
(B) Benzoic acid & Napthalene	(II) Sublimation
(C) Water & Aniline	(III) Distillation
(D) Napthalene & Sodium chloride	(IV) Crystallisation

Choose the correct answer from the options given below:

Given below are two statements:
Statement I : The non bio-degradable fly ash and slag from steel industry used by cement industry.
Statement II : The fuel obtained from plastic waste is lead free.
In the light of the above statements, choose the most appropriate answer from the options given below:

Low oxidation state of metals in their complexes are common when ligands :

Which anion will be formed when ethyl 3-oxobutanate is treated with alkali?

For a reaction, the rate constant K. is expressed as log₁₀ K=14.2-C/T. Activation energy of the reaction is

Consider the above reaction; which one of the following compounds does not produce acetanilide from aniline?

The Product 'A' is

This compound has both ionic and covalent bonds:

\(2\) \(mol\) of \(Hg(g)\) is combusted in a fixed volume bomb calorimeter with excess of \(O_2\) at 298K and 1 atm into \(HgO(s)\) During the reaction, temperature increases from \(2980\) \(K\) to \(3128\) \(K\). If heat capacity of the bomb calorimeter and enthalpy of formation of \(Hg(g)\) are \(2000\) \(kJ \;K^{-1}\) and \(6132\) \(kJ \;mol^{-1}\) at \(298\) \(K\), respectively, the calculated standard molar enthalpy of formation of \(HgO(s)\) at \(298\) \(K\) is \(X\) \(kJ \;mol^{-1}\) The value of | \(X\) | is [Given : Gas constant \(R\) =\(83\) \(J\) \(K^{-1}\) \(mol^{-1}\)] 

The treatment of an aqueous solution of $3.74\, g$ of $Cu \left( NO _3\right)_2$ with excess $KI $ results in a brown solution along with the formation of a precipitate.Passing $H _2 S$ through this brown solution gives another precipitate $X$ The amount of $X$ (in $g$ ) is ___ . [Given : Atomic mass of $H =1, N =14, O =16, S =32, K =39, Cu =63, I =127$ ]

A solution is prepared by mixing $0.01\, mol$ each of $H _2 CO _3, NaHCO _3, Na _2 CO _3$, and $NaOH$ in $100 \, mL$ of water $pH$ of the resulting solution is ___ [Given : $p K _{ a 1}$ and $p K _{ a 2}$ of $H _2 CO _3$ are $637$ and $1032$, respectively $; \log 2=030$ ]

The reaction of $HClO _3$ with $HCl$ gives a paramagnetic gas, which upon reaction with $O _3$ produces

The correct option(s) related to the extraction of iron from its ore in the blast furnace operating in the temperature range $900-1500 K$ is(are)

2 mol of Hg(g) is combusted in a fixed volume bomb calorimeter with excess of O₂ at 298 K and 1 atm into HgO(s). During the reaction, temperature increases from 298.0 K to 312.8 K. If heat capacity of the bomb calorimeter and enthalpy of formation of Hg(g) are 20.00 kJ K^–1 and 61.32 kJ mol^–1 at 298 K, respectively, the calculated standard molar enthalpy of formation of HgO(s) at 298 K is X kJ mol^–1. The value of |X| is _______.
[Given: Gas constant R = 8.3 J K^–1 mol^–1]

Which of the following is not a conductor?

Which of the following compounds can exhibit geometrical isomerism ?

For a, ẞ and y rays, the incorrect order/s is/are

Which of the following is (are) stronger acid than acetic acid ?

Select the chemicals which can act as nucleophile.

For complex compounds, the correct statements are:
(A) Number of unpaired electrons of both tetrahedral and octahedral complexes depends on the nature of the ligands.
 (B) In general, copper (II) and zinc (II) display coloured and colourless complex compounds, respectively.
 (C) Shape of co-ordination compounds does not depend on the hybridization of the central metal.
 (D) Nickel (II) complexes show diamagnetic and paramagnetic behaviour in square planer and octahedral structures, respectively.

Which of the following molecules is paramagnetic?

Which of the following structure is not meso-2,3-butanediol ?