Download App

Chemical Bonding and Molecular Structure — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryChemical Bonding and Molecular Structure5 Marks
Question
Define octet rule. Write its significance and limitations.
✓

Answer

Octet rule: Atoms of elements combine with each other in order to complete their respective octets so as to acquire the stable gas configuration.

Significance: It helps to explain why different atoms combine with each other to form ionic compounds or covalent compounds.

Limitations of Octet rule:

  • According to Octet rule, atoms take part in chemical combination to achieve the configuration of nearest noble gas elements. However, some of noble gas elements like Xenon have formed compounds with fluorine and oxygen. For example: XeF2, XeF4 etc.
    Therefore, validity of the octet rule has been challenged.
  • This theory does not account for shape of molecules.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Chemical Bonding and Molecular Structure→Chemical Bonding and Molecular Structure — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

What is ionization enthalpy? Explain its change in group and period of periodic table.
→
At 1127 K and 1 atmosphere pressure, a gaseous mixture of CO and $CO _2$ in equilibrium with solid carbon has 90.55\% CO by mass.
$
C(s)+CO_2(g) \rightleftharpoons 2 CO(g)
$
Calculate $K _{ C }$ for the reaction at the above temperature.
→
What is Lattice Enthalpy? How is its value determined with the help of Born-Haber cycle?
→
For the reaction:

$\text{N}_2(\text{g})+3\text{H}_2(\text{g})\rightleftharpoons2\text{NH}_3(\text{g})$

at 400K, Kp = 41. Find the value of Kp for each of the following reactions at the same temperature.

  1. $\text{2NH}_3(\text{g})\rightleftharpoons\text{N}_2(\text{g})+3\text{H}_2(\text{g})$

  2. $\frac{1}{2}\text{Na}(\text{g})+\frac{3}{2}\text{H}_2(\text{g})\rightleftharpoons\text{NH}_3(\text{g})$

  3. $2\text{N}_2(\text{g})+6\text{H}_2(\text{g})\rightleftharpoons4\text{NH}_3(\text{g})$

→
The first ionization enthalpy values (in kJ mol–1) of group 13 elements are:
B Al Ga In Tl
801 577 579 558 589
How would you explain this deviation from the general trend?
→
The average concentration of SO2 in atmosphere over a city on a certain day is 10 ppm, when the average temperature is 298K. Given that the solubility of SO2 in water at 298K is 1.3653mol/ L and the pKa of H2SO3 is 1.92, estimate the pH of acid rain on that day.
→
A compound on analysis found to contain following percentage composition:
Na = 43.4%, C = 11.4% and O = 45.3%. Determine the empirical and molecular formulae.
Given: the relative molecular mass of the compound is 106.
→
How many neutrons and protons are there in the following nuclei?
$\text{ }^{13}_{06}\text{C},\text{ }^{16}_{08}\text{O},\text{ }^{24}_{12}\text{Mg},\text{ }^{56}_{26}\text{Fe},\text{ }^{88}_{38}\text{Sr}$
→
What is meant by the term bond order? Calculate the bond order of : $\text{N}_2,\text{O}_2,\text{O}_2^+$ and $\text{O}_2^-$
→
  1. At 473K, equilibrium constant, K for decomposition of PCl5 is 8.3 × 10-3. If decomposition is depicted as

$\text{PCl}_5(\text{s})\rightleftharpoons\text{PCl}_3(\text{s})+\text{Cl}_2(\text{g});$

$\Delta_\text{r}\text{H}^\text{o}=124.0\text{kJ mol}^{-1}$

  1. Write an expression for Kc for the reaction.
  2. What is the value of Kc for the reverse reaction at same temperature.
  3. What would be the effect on Kc if:
  1. The pressure is increased?
  2. The temperature is increased?
  1. Write equilibrium constant for the following reactions:

  1. $\text{BaCO}_3(\text{s})\rightleftharpoons\text{BaO(s)}+\text{CO}_2(\text{g})$

  2. $\text{CH}_4(\text{g})+2\text{O}_2(\text{g})\rightleftharpoons\text{CO}_2(\text{g})+2\text{H}_2\text{O(g)}$

→