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?
Arrange the following compounds in increasing order of their property as indicated:
(i) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
(ii) CH3CH2CH(Br)COOH, CH3CH(Br)CH2COOH, (CH3)2CHCOOH, CH3CH2CH2COOH (acid strength)
(iii) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
(i)Ethanal, Propanal, Propanone, Butanone.
(ii)Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Hint:Consider steric effect and electronic effect.
Classify each of the following as being either a p-type or an n-type semiconductor:
(i) Ge doped with In
(ii) B doped with Si.
The decomposition of dimethyl ether leads to the formation of CH4, H2and CO and the reaction rate is given by
Rate = k [CH3OCH3]3/2
The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can also be expressed in terms of the partial pressure of dimethyl ether, i.e.,
Rate = k (PCH3OCH3)3/2
If the pressure is measured in bar andtime in minutes, then what are the units of rate and rate constants?
Why are solids rigid?
How is O3 estimated quantitatively?
Why are Mn2+compounds more stable than Fe2+ towards oxidation to their +3 state?
Give four examples of heterogeneous catalysis.
Write the monomers used for getting the following polymers. (i) Polyvinyl chloride (ii) Teflon (iii) Bakelite
What products would be formed when a nucleotide from DNA containing thymine is hydrolysed?