Archives

the electron gain enthalpy of fluorine chlorine bromine and iodine respectively are

a) -333, -325, -349 and -296 b) -333, -349, -325 and -296 c) -296, -325, -333 and -349 d) -349, -333, -325 and -296 Answer: b Cl > F >... View Article

A solution of m-chloroaniline, m-chlorophenol and m-chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO₃ to give fraction A. The left over organic phase was extracted with dil. NaOH solution to give fraction B. The final organic layer was labelled as fraction C. Fractions A, B and C, contain respectively:

a) m-chlorobenzoic acid, m-chlorophenol and m-chloroaniline b) m-chlorophenol, m-chlorobenzoic acid and m-chloroaniline c) m-chloroaniline,... View Article

Given that the standard potential; (Eo) of Cu²⁺/Cu and Cu⁺/Cu are 0.34 V and 0.522 V respectively, the E^o of Cu²⁺/Cu⁺ is :

a) +0.158 V b) -0.158 V c) 0.182 V d) -0.182 V Answer: a Cu2+ + 2e- Cu E° = 0.340 V Cu - Cu+ + e- E°= -0.522 V Cu2+ + e- ⇾ Cu+ E° = ?... View Article

What is the product X used for in the the following reaction:

a) in protein estimation as an alternative to ninhydrin b) as food grade colourant c) in laboratory test for phenols d) in acid-base... View Article

1-methyl ethylene oxide when treated with an excess of HBr produces:

Answer: c... View Article

The IUPAC name of the complex [Pt(NH₃)₂Cl(NH₂CH₃)]Cl is :

a) Diamminechlorido (methanamine) platinum (II) chloride b) Bisammine (methanamine) chloridoplatinum (II) chloride c) Diammine (methanamine)... View Article

In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is :

a) less efficient as it exchanges only anions b) more efficient as it can exchanges only cations c) less efficient as the resins cannot be... View Article

The theory that can completely/ properly explain the nature of bonding in [Ni(CO)₄] is:

a) Werner’s theory b) Crystal Field Theory c) Molecular Orbital Theory d) Valence Bond Theory Answer: c... View Article

The purest form of commercial iron is:

a) cast iron b) wrought iron c) scrap iron and pig iron d) pig iron p>Answer: b... View Article

The number of orbitals associated with quantum number n = 5, ms = +½ is :

a) 11 b) 15 c) 25 d) 50 Answer: c n = 5; l = (n – 1) = 4; hence the possible sub-shells for n=5 are: 5s, 5p, 5d, 5f and 5g. The number of... View Article

What is the product of the following reaction?

Hex-3-ynal (i) NaBH4 (ii) PBr3 (iii) Mg/ether (iv) CO2/H3O+ Answer: b... View Article

The increasing order of pK_b for the following compounds will be :

(i) H2N-CH=NH (ii) (iii) CH3NHCH3 a) ii < iii < i b) iii < i < ii c) i < ii < iii d) ii < i < iii Answer: d... View Article

Amongst the following statements, that which was not proposed by Dalton was :

a) matter consists of indivisible atoms. b) when gases combine or reproduced in a chemical reaction they do so in a simple ratio by volume... View Article

The atomic radius of Ag is closest to :

a) Ni b) Cu c) Au d) Hg Answer: c Because of Lanthanide contraction, an increase in Zeff is observed and so, the size of Au instead of... View Article

At 35⁰C, the vapour pressure of CS₂ is 512 mm Hg and that of acetone is 344 mm Hg. A solution of CS₂ in acetone has a total vapour pressure of 600 mm Hg. The false statement amongst the following is :

a) CS2 and acetone are less attracted to each other than to themselves b) heat must be absorbed in order to produce the solution at 350C c)... View Article

The relative strength of interionic/ intermolecular forces in decreasing order is:

a) ion-dipole > dipole-dipole > ion-ion b) dipole-dipole > ion-dipole > ion-ion c) ion-ion > ion-dipole > dipole-dipole d)... View Article

In the following reaction, compound Q is obtained from compound P via an ionic intermediate.

What is the degree of unsaturation of Q? Answer: 18 The total degree of unsaturation = 18... View Article

Uranium 238 is known to undergo radioactive decay to form isotope of lead Pb 206 by emitting alpha and beta particles.

A rock initially contained 68 × 10−6 g of in three half-lives is × 1018, then what is the value of ? Answer: 1.21 Mole... View Article

Aluminum reacts with sulfuric acid to form aluminum sulfate and hydrogen. What is the volume of hydrogen gas in liters (L) produced at 300 K and 1.0 atm pressure, when 5.4 g of aluminum and 50.0 mL of 5.0 M sulfuric acid are combined for the reaction?

(Use molar mass of aluminum as 27.0 g mol−1, = 0.082 atm L mol−1 K−1) Answer: 6.15 Liter 2Al +... View Article

Consider a 70% efficient hydrogen-oxygen fuel cell working under standard conditions at 1 bar and 298 K.

Its cell reaction is H2(g) + ½ O2(g) → H2O(l) The work derived from the cell on the consumption of 1.0 × 10−3mol of... View Article