Following data are obtained for the reaction:
N2O5 → 2NO2 + 1/2 O2
t/s | 0 | 300 | 600 |
[N2O5] / mol L-1 | 1.6 x 10-2 | 0.8 x 10-2 | 0.4 x 10-2 |
(a) Show that it follows first order reaction.
(b) Calculate the half-life.
(Given: log 2 = 0.3010 , log 4 = 0.6021 )
For first order reaction:
k = 2.303 / t Log a0 /a
where a0 = initial concentration
and a = remaining concentration
At t = 300 seconds
K1 = 2.303/300 log 1.6 x 10-2 / 0.8 x 10-2
K1 = 2.303/300 log 2
K1 = 2.303/300 x 0.3010
K1 = 0.00231 s-1
Now at t = 600 seconds
K2 = 2.303/600 log 1.6 x 10-2 / 0.4 x 10-2
K2 = 2.303/600 log 4
K2 = 2.303/600 x 0.6021
K2 = 0.00231 s-1
Since the value of K is contant in both the situation so it is a first order reaction.
K = 0.00231 s-1
t1/2 = 0.693 / 0.00231 = 300 seconds.
How the following conversions can be carried out?
(i) Propene to propan-1-ol
(ii) Ethanol to but-1-yne
(iii) 1-Bromopropane to 2-bromopropane
(iv) Toluene to benzyl alcohol
(v) Benzene to 4-bromonitrobenzene
(vi) Benzyl alcohol to 2-phenylethanoic acid
(vii) Ethanol to propanenitrile
(viii) Aniline to chlorobenzene
(ix) 2-Chlorobutane to 3, 4-dimethylhexane
(x) 2-Methyl-1-propene to 2-chloro-2-methylpropane
(xi) Ethyl chloride to propanoic acid
(xii) But-1-ene to n-butyliodide
(xiii) 2-Chloropropane to 1-propanol
(xiv) Isopropyl alcohol to iodoform
(xv) Chlorobenzene to p-nitrophenol
(xvi) 2-Bromopropane to 1-bromopropane
(xvii) Chloroethane to butane
(xviii) Benzene to diphenyl
(xix) tert-Butyl bromide to isobutyl bromide
(xx) Aniline to phenylisocyanide
Give simple chemical tests to distinguish between the following pairs of compounds.
(i) Propanal and Propanone
(ii) Acetophenone and Benzophenone
(iii) Phenol and Benzoic acid
(iv) Benzoic acid and Ethyl benzoate
(v) Pentan-2-one and Pentan-3-one
(vi) Benzaldehyde and Acetophenone
(vii) Ethanal and Propanal
A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.
A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL-1, then what shall be the molarity of the solution?
Henry's law constant for CO2 in water is 1.67 x 108Pa at 298 K. Calculate the quantity of CO2in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.
Calculate the mass of a non-volatile solute (molar mass 40 g mol-1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.
The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.
Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
How many mL of 0.1 M HCl are required to react completely with 1 g mixture of Na2CO3 and NaHCO3 containing equimolar amounts of both?
If NaCl is doped with 10-3mol % of SrCl2, what is the concentration of cation vacancies?
Distinguish between the meaning of the terms adsorption and absorption. Give one example of each.
In terms of band theory, what is the difference
(i) Between a conductor and an insulator
(ii) Between a conductor and a semiconductor
What are the common types of secondary structure of proteins?
Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.
Give IUPAC names of the following ethers:
How can you prepare Cl2 from HCl and HCl from Cl2? Write reactions only.
Arrange the following in the order of property indicated for each set:
(i) F2, Cl2, Br2, I2- increasing bond dissociation enthalpy.
(ii) HF, HCl, HBr, HI - increasing acid strength.
(iii) NH3, PH3, AsH3, SbH3, BiH3- increasing base strength.
Give the formula and describe the structure of a noble gas species which is isostructural with:
(i) ICl-4
(ii) IBr-2
(iii) BrO-3
Comment on the statement that "colloid is not a substance but a state of substance".
For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained.
t (sec) | P(mm of Hg) |
0 | 35.0 |
360 | 54.0 |
720 | 63.0 |
Calculate the rate constant