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Why beryllium and magnesium do not impart colour to the flame?

When alkaline earth metals are heated, electrons are stimulated to higher energy levels, and energy is released in the form of visible light when... View Article

Ionic mobility of Li+ is greater than that of Na+ .

Li+ion has high charge density and higher hydration power when dissolved in water because of the smallest size of lithium ion, so the effective... View Article

What is the compressibility factor (Z) for 0.02 mole of a Van Der Waals gas at pressure of 0.1 atm. Assume the size of gas molecules is negligible. Given RT=20Latm(mol)⁻¹ and a = 1000atmL²mol⁻²

Given that gas the Van Der Waals gas at pressure of 0.1atm Number of moles is 0.02 The value of a can be given as a=PV2/n2 Substitute the... View Article

Which of the following are exothermic processes? (i) Reaction of water with quicklime. (ii) Dilution of an acid. (iii) Evaporation of water. (iv) Sublimation of camphor (crystals). A. (i) and (ii) B. (ii) and (iii) C. (i) and (iv) D. (iii) and (iv)

An exothermic process is one in which heat energy is released (given away). The heat energy is on the product's side in the thermochemical... View Article

The lattice energy of NaCl is 788kJ/mol. This means that 788kJ of energy is required.

Answer: (B) to separate one mole of solid NaCl into one mole of Na+and one mole of Cl(g) to infinite distance. Since it is impossible to... View Article

How would you explain the fact that first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?

Now, electronic configuration of sodium (Na): 1s22s22p63s1 Electronic configuration of magnesium (Mg): 1s22s22p63s2 First ionization enthalpy... View Article

The maximum covalency of nitrogen is: (A) 3 (B) 4 (C) 5 (D) 6

Since nitrogen has an atomic number of 7, its electronic configuration is 1s22s22p3. We can observe that the N atom possesses two 2s electrons... View Article

How to find antibonding electrons in O2?

According to the MOT (point 3) the electrons should be filled in the molecular orbitals according to their increasing order of energy as shown... View Article

The correct order of the oxidizing power of halogens is:

. Since fluorine is the strongest oxidizing agent amongst halogen, it will oxidize all other halide ions to the corresponding halogen in solution... View Article

Calculate the % of water of crystallization in washing soda crystals.

To calculate the mass percent of the water of crystallization in the given compound, washing soda by using the following equation: the formula of... View Article

Does ozone have coordinate bond?

Co-ordinate bond is a type of alternate covalent bond that is formed by sharing of electron pair from a single atom. Both shared electrons are... View Article

P4O6 reacts with water to give:

P4O6 reacts with water to give phosphoric acid. The chemical name of P4O6 is Phosphorus trioxide. It is formed by burning phosphorus in the... View Article

Which of the following has the highest nucleophilicity? A.F− B.OH− C.CH3− D.NH2−

Electrophiles are normally positively charged, whereas nucleophiles are negatively charged and may include a lone pair or neutral electrons,... View Article

In an imaginary atmosphere, the air exerts a small force F on any particle in the direction of the particle’s motion. A particle of mass m projected upwards takes a time t1 in reaching the maximum height and t2 in the return journey to the original point. Then: A. t1t2 C. t1=t2

The force exerted by the air on the particle aids the particle's speed. When a particle goes upwards, we know that the direction of gravitational... View Article

Hybridisation of C2 and C3 of H3C−CH=C=CH−CH3 are (A)- sp,sp3 (B)- sp2,sp (C)- sp2,sp2 (D)- sp,sp

Amswer: (b) The presented compound is symmetric in nature, with the same number of groups connected to C-1 and C-5, C-2 and C-4. The centre... View Article

In which of the following, functional group isomerism is not possible? A.Alcohols B.Aldehyde C.Alkyl halides D.Cyanides

Answer: (c) Alkyl halides Alcohols and ethers are functional group isomers. The hydroxyl group, - OH, is the functional group in alcohols,... View Article

Which of the following compounds has zero dipole moment? (A) 1,4−dichlorobenzene (B) 1,2−dichlorobenzene (C) 1,3−dichlorobenzene (D) 1−chloro−2−methylbenzene

Trans-dichlorobenzene has zero dipole moment as it is symmetrical and the dipole moment will cancel out. A dipole moment arises in any system... View Article

Which of the following carbonyls will have the strongest C−O bond? A) Mn(CO)⁺⁶ B) Cr(CO)⁶ C) V (CO)⁻⁶ D) Fe(CO)⁵

The highest occupied molecular orbital in the carbonyl CO molecule contains the lone pair of electrons that are projecting away from the carbon... View Article

Reaction between nitrogen and oxygen takes place as following: 2N₂(g) + O₂ ⇌ 2N₂O(g) If a mixture of 0.482 mole ofN2 and 0.933 mole of _O2 is placed in a reaction vessel of volume 10 litre and allowed to form at a temperature for which KC = 2.0 x 10^-37 litre mol-1 . Determine the composition of the equilibrium mixture.

The reaction given in the question – 2N2(g)+O2(g)⇌2N2O(g) The value for equilibrium constant (Kc) of this reaction will be –... View Article

Which of the following molecules have zero dipole moment and tetrahedral structure? (A) CCl4 (B) SnCl2 (C) SnCl4 (D) CO2

Answer: (a) and (c) Tetrahedral symmetry exists in the CCl4 molecule. As a consequence, the dipole moment of the three CCl bonds on one side... View Article

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