The decomposition of A into product has value of k as 4.5 x 103 s-1 at 10°C and energy of activation 60 kJ mol-1. At what temperature would k be 1.5 x 104 s-1?
From Arrhenius equation, we obtain
log k2/k1 = Ea / 2.303 R (T2 - T1) / T1T2
Also, k1 = 4.5 × 103 s - 1
T1 = 273 + 10 = 283 K
k2 = 1.5 × 104 s - 1
Ea = 60 kJ mol - 1 = 6.0 × 104 J mol - 1
Then,
= 297 K = 24°C
Hence, k would be 1.5 × 104 s - 1 at 24°C.
The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample.
For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction.
The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. Calculate the energy of activation of the reaction assuming that it does not change with temperature.
A first order reaction takes 40 min for 30% decomposition. Calculate t1/2.
In a reaction, 2A → Products, the concentration of A decreases from 0.5 mol L-1 to 0.4 mol L-1 in 10 minutes. Calculate the rate during this interval?
The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y?
During nuclear explosion, one of the products is 90Sr with half-life of 28.1 years. If 1μg of 90Sr was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 years and 60 years if it is not lost metabolically.
Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law, with t1/2 = 3.00 hours. What fraction of sample of sucrose remains after 8 hours?
For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.
The following data were obtained during the first order thermal decomposition of SO2Cl2at a constant volume.
SO2Cl2(g) → SO2(g) + Cl2(g)
Experiment |
Time/s - 1 |
Total pressure/atm |
1 | 0 | 0.5 |
2 | 100 | 0.6 |
Calculate the rate of the reaction when total pressure is 0.65 atm.
Write the formulas for the following coordination compounds:
(i) Tetraamminediaquacobalt (III) chloride
(ii) Potassium tetracyanonickelate(II)
(iii) Tris(ethane-1,2-diamine) chromium(III) chloride
(iv) Amminebromidochloridonitrito-N-platinate(II)
(v) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate
(vi) Iron(III) hexacyanoferrate(II)
(i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N
(ii) Write IUPAC names of all the isomers.
(iii) What type of isomerism is exhibited by different pairs of amines?
Why are solids rigid?
Write any two characteristics of Chemisorption.
Write the structures of the following compounds.
(i) α-Methoxypropionaldehyde
(ii) 3-Hydroxybutanal
(iii) 2-Hydroxycyclopentane carbaldehyde
(iv) 4-Oxopentanal
(v) Di-sec-butyl ketone
(vi) 4-Fluoroacetophenone
Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?
Why are pentahalides more covalent than trihalides?
Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?
Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.
Write structures of the following compounds:
(i) 2-Chloro-3-methylpentane
(ii) 1-Chloro-4-ethylcyclohexane
(iii) 4-tert. Butyl-3-iodoheptane
(iv) 1,4-Dibromobut-2-ene
(v) 1-Bromo-4-sec. butyl-2-methylbenzene
Explain why
(i) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride?
(ii) alkyl halides, though polar, are immiscible with water?
(iii) Grignard reagents should be prepared under anhydrous conditions?
What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.
Write the order of thermal stability of the hydrides of Group 16 elements.
Write two main functions of carbohydrates in plants.
Arrange the following metals in the order in which they displace each other from the solution of their salts.
Al, Cu, Fe, Mg and Zn
Write chemical reaction for the preparation of phenol from chlorobenzene.
Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.
Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s) takes place.
Further show:
(i) Which of the electrode is negatively charged?
(ii) The carriers of the current in the cell.
(iii) Individual reaction at each electrode.
A solution containing 30 g of non-volatile solute exactly in 90 g of water has a vapour pressure of 2.8 kPa at 298 K. Further, 18 g of water is then added to the solution and the new vapour pressure becomes 2.9 kPa at 298 K. Calculate:
1) Molar mass of the solute
2) Vapour pressure of water at 298 K.
What is tincture of iodine ? What is its use ?
Please explain the log solution