List of top Chemistry Questions

What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of \(ICl\) was \(0.78 \ M\)?
\(2ICl (g) ⇋ I_2 (g) + Cl_2 (g); \ K_c = 0.14\)
Kp = 0.04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C2H6 when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium?
\(C_2H_6 (g) ⇋ C_2H_4 (g) + H_2 (g)\)
Is there any change in the hybridisation of B and N atoms as a result of the following reaction? 
\(BF_3+ NH_3 \rightarrow F_3B.NH_3\)
Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in \(C_2H_4\) and \(C_2H_2\) molecules.
What is the total number of sigma and pi bonds in the following molecules?
  1. \(C_2H_2\) 
  2. \(C_2H_4\)
The electron energy in hydrogen atom is given by \(E_n = \frac {(–2.18×10^{–18})}{n^2} \ J\). Calculate the energy required to remove an electron completely from the n = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?
Chlorine is used to purify drinking water. Excess of chlorine is harmful. The excess of chlorine is removed by treating with sulphur dioxide. Present a balanced equation for this redox change taking place in water.
Similar to electron diffraction, a neutron diffraction microscope is also used for the determination of the structure of molecules. If the wavelength used here is 800 pm, calculate the characteristic velocity associated with the neutron.
In Ostwald's process for the manufacture of nitric acid, the first step involves the oxidation of ammonia gas by oxygen gas to give nitric oxide gas and steam. What is the maximum weight of nitric oxide that can be obtained starting only with 10.00 g. of ammonia and 20.00 g of oxygen?
Calculate the wavelength of an electron moving with a velocity of \(2.05×10^7 \ ms^{–1}\).
The mass of an electron is 9.1 × 10–31 kg. If its K.E. is 3.0 × 10–25 J, calculate its wavelength.
Consider the reactions: 
(a) \(6 \,CO_2(g) + 6H_2O(l) \rightarrow C_6H_{12}O_6(aq) + 6O_2(g)\) 
(b) \(O_3(g) + H_2O_2(l) \rightarrow  H_2O(l) + 2O_2(g)\) 
Why it is more appropriate to write these reactions as: (a) \(6\,CO_2(g) + 12H_2O(l) \rightarrow  C_6H_{12}O_6(aq) + 6H_2O(l) + 6O_2(g)\) 
(b) \(O_3(g) + H_2O_2(l) \rightarrow H_2O(l) + O_2(g) + O_2(g)\) 
Also suggest a technique to investigate the path of the above (a) and (b) redox reactions.
Which hybrid orbitals are used by carbon atoms in the following molecules? 
  1. \(CH_3-CH_3\); 
  2. \(CH_3-CH=CH_2\); 
  3. \(CH_3-CH_2-OH\); 
  4. \(CH_3-CHO\) 
  5. \(CH_3COOH\)
How many electrons in an atom may have the following quantum numbers?
  1. n = 4, ms = – \(\frac 12\)
  2. n = 3, l = 0
What do you understand by bond pairs and lone pairs of electrons? Illustrate by giving one example of each type.
What are hybridization states of each carbon atom in the following compounds? 
\(CH_2=C=O,\, CH_3CH=CH_2\),\((CH_3)_2CO, \,CH_2=CHCN, \,C_6H_6.\)
A certain particle carries 2.5 × 10–16 C of static electric charge. Calculate the number of electrons present in it.
If the velocity of the electron in Bohr’s first orbit is 2.19×106ms–1, calculate the de Broglie wavelength associated with it.
Indicate the σ and π bonds in the following molecules. \(C_6H_6, C_6H_{12}, CH_2Cl_2, CH_2=C=CH_2, CH3NO2, HCONHCH_3.\)
Distinguish between a sigma and a pi bond.
Write bond line formulas for, Isopropyl alcohol, 2,3-Dimethylbutanal, Heptan-4-one.
Calculate the oxidation number of Sulphur, chromium, and nitrogen in
\(H_2SO_5\), \(Cr_2O_7^{2−}\) and \(NO_3^−\). Suggest structure of these compounds. Count for the fallacy.
An ion with mass number 37 possesses one unit of negative charge. If the ion conatins 11.1% more neutrons than the electrons, find the symbol of the ion.
Using s, p, d notations, describe the orbital with the following quantum numbers.
  1. n=1, l=0
  2. n = 3, l=1
  3. n = 4, l =2
  4. n=4, l=3
Explain the formation of \(H_2\) molecule on the basis of valence bond theory.