List of top Chemistry Questions

True/False: The compounds \([\text{CoCl}_2(\text{NH}_3)_4]\text{NO}_2\) and \([\text{CoCl}(\text{NO}_2)(\text{NH}_3)_4]\text{Cl}\) show coordination isomerism.
Transition elements or their compounds act as catalysts. Explain why.
Explain giving two reasons why haloarenes are less reactive towards nucleophilic substitution reactions than haloalkanes.
Explain the mechanism of Substitution Nucleophilic Bimolecular (SN\(_2\)) reaction of haloalkanes with a suitable example.
Why do Ce and Tb show +4 oxidation state?
Define lanthanoid contraction.
Write down two similarities between lanthanoids and actinoids.
Which element of the 3d transition series has the lowest enthalpy of atomisation and why?
Write down the following reactions: (a) Sandmeyer reaction (b) Hoffmann ammonolysis reaction (c) Wurtz–Fittig reaction (d) Finkelstein reaction (e) Friedel–Crafts alkylation
Complete the following reactions: (i) \(\ \text{CH}_3\text{OH} + \text{I}_2 + \text{NaOH} \xrightarrow{\Delta} \ ?\) (ii) \(\ \text{CH}_3\text{CH}_2\text{OH} \xrightarrow[\;523\,\text{K}\;]{\text{Al}_2\text{O}_3} \ ?\) (iii) \(\ \text{C}_2\text{H}_5\text{ONa} + \text{C}_2\text{H}_5\text{Br} \xrightarrow{\Delta} \ ?\)
What is Lucas reagent? Write down Lucas test for distinction between primary, secondary and tertiary alcohols.
Differentiate between fibrous and globular proteins.
Lower aliphatic amines are soluble in water. Why?
Write down a test to distinguish between aromatic primary amines and aliphatic primary amines.
Starting from 100 g of a radioactive substance, 2.5 g was left after 5 years. If its radioactive decay follows first order kinetics, calculate: (i) Rate constant for the decay of the radioactive substance (ii) The amount of substance left after one year (iii) The time required for half of the substance to decay
Three electrolytic cells A, B and C containing electrolytes of zinc sulphate, silver nitrate and copper sulphate respectively were connected in series. A steady current of 1.5 A was passed through them until 1.45 g of silver were deposited at the cathode of cell B. (i) How long did the current flow? (ii) What weight of copper and zinc get deposited?
Write down the following reactions: (i) Aldol condensation (ii) HVZ reaction
Explain the mechanism of acidic dehydration of ethyl alcohol to form ethene.
Define coordination number.
Alkylamines are more basic than ammonia. Explain why?
Write down the following reactions: (i) Carbylamine reaction (ii) Reaction between benzene diazonium chloride and phenol in basic medium
Explain why carboxylic acids exist as associated molecules.
How will you convert phenol to salicylaldehyde?
Calculate the number of molecules of oxalic acid \((\text{H}_2\text{C}_2\text{O}_4\cdot2\text{H}_2\text{O})\) in 100 mL of 0.2 N oxalic acid solution.
Shazia removed the outer hard shells of two different eggs. She then placed one egg in pure water and the other egg in a saturated solution of sucrose. What change is she likely to observe in the eggs after a few hours? Explain it.