Cool Chemistry

Question on Quantum Numbers

Mon, 29 Oct 2012 20:00:21 +0530

How many electrons with azimuthal quantum number, l = 3 are present in an atom having atomic number 54?

Question on Atomic Weight

Sun, 28 Oct 2012 20:00:35 +0530

A mono atomic ion has the same atomic number and same atomic weight as its neutral atom. Is this statement true or false?

Question on Addition Reaction

Sat, 27 Oct 2012 20:00:34 +0530

When but-3-en-2-ol reacts with aq. HBr, how many products are formed and what are they?

Question on Nucleophilic Strength

Fri, 26 Oct 2012 20:00:19 +0530

Among CH₃^-, NH₂^-, OH^-and F^-which one is the best Nucleophile?

Question on Photochemical Bromination

Thu, 25 Oct 2012 20:00:44 +0530

What is the relative amounts of 1-bromopropane and 2-bromopropane obtained from the photochemical bromination of propane, if the relative reactivity of 1° : 2° : 3° Hydrogens to photochemical bromination is 1 : 82 : 1600?

Question on Unsaturation

Wed, 24 Oct 2012 20:00:44 +0530

The Molecular formula of an organic compound is C₁₀H₁₆and takes 2 moles of hydrogen per mole of it. How many rings are likely to be present in its structure?

Question on Photochemical Chlorination

Tue, 23 Oct 2012 19:35:14 +0530

Isopentane, (CH₃)₂CH.CH₂.CH₃ can form four isomeric monochloro derivatives on photochemical Chlorination. How many of these are optically active?

Question on Nitrogen Oxides

Mon, 22 Oct 2012 19:59:27 +0530

Which oxide of Nitrogen is produced on heating a mixture of ammonium sulphate and sodium nitrate?

Question on Gaseous State

Sun, 21 Oct 2012 19:20:10 +0530

A gas is heated in such a way that its pressure and volume both becomes double. Then by decreasing temperature, some of the molecules of the air have been taken in container to maintain the doubled volume and pressure. Assuming one-fourth of initial number of moles has been taken in for the purpose, by what fraction the temperature must have been raised finally of initial absolute temperature?

Question on Dehydration

Sat, 20 Oct 2012 20:00:24 +0530

What does Orthophosphoric Acid give on strong heating?

Question on Nodal Planes

Fri, 19 Oct 2012 19:03:38 +0530

How many nodal planes are present in a p_x orbital?

Question on Gaseous State

Thu, 18 Oct 2012 19:29:37 +0530

If the Compressibility Factor of a gas is less than unity at STP, will the molar volume of the gas be greater or lesser than 22.4L at STP?

Question on pH

Wed, 17 Oct 2012 19:56:04 +0530

A weak base BOH reacts with 0.1M HCl. The dissociation constant of BOH is 10^–6. When 50 ml of 0.1N BOH reacts with HCl, what will the pH of the solution be at the neutralization point of the reaction?

Question on Chemical Kinetics

Tue, 16 Oct 2012 20:00:18 +0530

If 10^–5% reactant molecules cross over the barrier in transition state at 298K, what is the activation barrier needed to cross the transition state?

Question on Qualitative Analysis

Mon, 15 Oct 2012 19:52:43 +0530

Can Tollen’s Reagent be used to distinguish between methanoic and ethanoic acids?

Question on Redox Reaction

Sun, 14 Oct 2012 19:19:34 +0530

1 mole of hydrazine, N₂H₄ reacts with one mole of selenic acid, H₂SeO₃, the latter is reduced to selenium. What is hydrazine converted into? Is it N₂ or NH₃?

Question on Organic Reaction

Thu, 20 Sep 2012 19:49:12 +0530

An Organic Compound A of molecular formula C₄H₁₀O₃ reacts with excess hydrogen bromide to give ethylene dibromide as the only product. What is the name of A?

Question on Nucleophilic Substitution Reaction

Wed, 19 Sep 2012 19:59:48 +0530

Iodide ion is a good nucleophile as well as a good leaving group in nucleophilic substitution reactions. Is this statement true or false?

Question on Electrophilic Aromatic Substitution

Tue, 18 Sep 2012 19:53:15 +0530

The following two methods can be used to convert benzene into ethylbenzene;

1. Reacting benzene with ethyl benzene and aluminium chloride (Friedel Craft’s Alkylation)

2. Reacting benzene with acetyl chloride and aluminium chloride to produce methyl phenyl ketone (Friedel Craft’s Acylation) followed by Clemmensen’s Reduction

Which out of the above two is the best suited method and why?

Question on Ring Opening

Mon, 17 Sep 2012 19:53:56 +0530

Cyclohexane does not undergo ring opening compared to cyclopropane molecule during reactions. Why?