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What is the state of hybridisation of boron and oxygen atoms in boric acid(H3BO3 ) respectively?

H3BO3 is the chemical formula for boric acid. Three hydroxyl groups create a connection with the central boron atom. Boron's outermost valence... View Article

A photosensitive metallic surface is illuminated alternately with lights of wavelength 3100 A and 6200 A. It is observed that maximum speeds of the photoelectrons in two cases are in the ratio 2:1. The work function of the metal is (hc = 12400 eVA).

a photosensitive metallic surface is illuminated alternatively with lights of wavelength 3100 A and 6200 A. Also, the maximum speeds of the... View Article

A certain gas takes three times as long to effuse out as helium. Its molecular mass will be A) 36u B) 64u C) 9u D) 27u

Graham law of effusion states that effusion of any gas is inversely proportional to the square of its molecular mass or its density. In... View Article

Which of the following has minimum bond length? A.O₂⁺ >B.O₂⁻ C.O₂²⁻ D.O₂

Answer: (a) The most essential rule of the VSEPR theory is that bond angles around a core atom should be chosen to reduce total repulsion... View Article

In which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three:(A) PCl₅ (B) SF₄ (C) I₃⁻ (D) SbCl₅²⁻

Answer: (d) To predict the hybridization of the molecule by using the below formula, H=1/2[V+M−C+A] Where H = number of orbitals in... View Article

But-1-ene in reaction with HCl in the presence of sodium peroxide yields.

The given compound is But-1-ene. CH3−CH2−CH = CH2 According to Markovnikov’s rule, the given alkene reacts with HCl in the presence of sodium... View Article

Under what conditions a bimolecular reaction may be kinetically of first order?

The pseudo unimolecular reaction is one in which one reactant is taken in excess, resulting in its concentration being constant even after... View Article

What happens when chlorine reacts with cold and dilute solution of sodium hydroxide?

Sodium chloride reacts with chlorine in different ways. For hot and concentrated there is different reaction and cold and dilute there is... View Article

Which of the following statements are correct for SO2 gas? (i) It acts as bleaching agent in moist conditions. (ii) It’s molecule has linear geometry. (iii) It’s dilute solution is used as disinfectant. (iv) It can be prepared by the reaction of dilute H2SO4 with metal sulphide.

Answer: (i), (iii) SO2 is used in the bleaching of wool and silk and as an antichlor, disinfectant, and preservative. Sulfur dioxide, (SO2),... View Article

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

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