Indicate the σ and π bonds in the following molecules :
(i) C6H6,
(ii) C6H12,
(iii) CH2Cl2,
(iv) CH2=C=CH2,
(v) CH3NO2,
(vi) HCONHCH3
(i) C6H6
There are six C-C sigma (σC-C) bonds, six C-H sigma (σC-H) bonds and three C=C pi (πC-C) resonating bonds in this compound.
(ii) C6H12
There are six C-C sigma (σC-C) bonds and twelve C-H sigma (σC-H) bonds in this compound.
(iii) CH2Cl2
There two C-H sigma (σC-H) bonds and two C-Cl sigma (σC-Cl) bonds in this compound.
(iv) CH2=C=CH2
There are two C-C sigma (σC-C) bonds, four C-H sigma (σC-H) bonds, and two C=C pi (πC-C) bonds in this compound.
(v) CH3NO2
There are three C-H sigma (σC-H) bonds, one C-N sigma (σC-N) bond, one N-O sigma (σN-O) bond and one N=O pi (πN-O) bond in this compound.
(vi) HCONHCH3
There are two C-N sigma (σC-N) bonds, four C-H sigma (σC-H) bonds, one N-H sigma bond, and one C=O pi (πC-O) bond in this compound.
The mass of an electron is 9.1 × 10–31 kg. If its K.E. is 3.0 × 10–25 J, calculate its wavelength.
Calculate the amount of carbon dioxide that could be produced when
(i) 1 mole of carbon is burnt in air.
(ii) 1 mole of carbon is burnt in 16 g of dioxygen.
(iii) 2 moles of carbon are burnt in 16 g of dioxygen.
Calculate the wavelength of an electron moving with a velocity of 2.05 × 107 ms–1.
Balance the following redox reactions by ion – electron method :
(a) MnO4 – (aq) + I – (aq) → MnO2 (s) + I2(s) (in basic medium)
(b) MnO4 – (aq) + SO2 (g) → Mn2+ (aq) + HSO4– (aq) (in acidic solution)
(c) H2O2 (aq) + Fe 2+ (aq) → Fe3+ (aq) + H2O (l) (in acidic solution)
(d) Cr2O7 2– + SO2(g) → Cr3+ (aq) + SO42– (aq) (in acidic solution)
In a process, 701 J of heat is absorbed by a system and 394 J ofwork is done by the system. What is the change in internal energy for the process?
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
In a reaction A + B2 → AB2 Identify the limiting reagent, if any, in the following reaction mixtures.
(i) 300 atoms of A + 200 molecules of B
(ii) 2 mol A + 3 mol B
(iii) 100 atoms of A + 100 molecules of B
(iv) 5 mol A + 2.5 mol B
(v) 2.5 mol A + 5 mol B
At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?
Which one of the following will have largest number of atoms?
(i) 1 g Au (s)
(ii) 1 g Na (s)
(iii) 1 g Li (s)
(iv) 1 g of Cl2(g)
Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure. What will be its density at STP?
The enthalpies of all elements in their standard states are:
(i) unity
(ii) zero
(iii) < 0
(iv) different for each element
What do you mean by ozone hole? What are its consequences?
What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, Ksp is 9.1 x 10-6).
Ionic product of water at 310 K is 2.7 x 10-14. What is the pH of neutral water at this temperature?
Why is it necessary to use acetic acid and not sulphuric acid for acidification of sodium extract for testing sulphur by lead acetate test?
A 0.02 M solution of pyridinium hydrochloride has pH = 3.44. Calculate the ionization constant of pyridine
Discuss the pattern of variation in the oxidation states of
(i) B to Tl and (ii) C to Pb.
Enthalpies of formation of CO(g), CO2(g), N2O(g) and N2O4(g) are –110, – 393, 81 and 9.7 kJ mol–1 respectively. Find the value of ΔrH for the reaction:
N2O4(g) + 3CO(g) → N2O(g) + 3CO2(g)
What effect does branching of an alkane chain has on its boiling point?
The ionization constant of nitrous acid is 4.5 x 10-4. Calculate the pH of 0.04 M sodium nitrite solution and also its degree of hydrolysis.
VERY HELPFUL!!!!