CHEMISTRY (FULL TEST- II)
Time : Two Hours Maximum Marks : 100
(i) Attempt all questions.
(ii) Start each question on a fresh page.
(iii) Answers of all parts of a question should be given at one place.
(iv) Each question carries TEN Marks.
(v) Use of calculator is NOT PERMITTED.
(vi) Use of logarithmic table is PERMITTED.
Name of the candidate : ………………………………………..
Enrollment Number : ………………………………………..
- The conversion of trypsinogen (A) into trypsin (B) in an autocatalytic reaction A ® B, where B catalyzes the reaction. The rate equation is = kxy, where x and y are concentrations of trypsinogen and tripsin at time t. Integrate this equation for initial conc. = X0 and Y0 for A and B and show that kt = .
- The molar volume of helium at 10.1325 MPa and at 273 K is 0.011705 of its molar volume at 101.325 K Pa at 273 K. Calculate the radius of helium atom.
- A 1.0 ´ 10–3 M solution of AgNO3 is made 0.20 M in NH3. What are the concentrations of Ag+, Ag (NH3)+, Ag(NH3)2+, in the resulting solution.
Given Ag(NH3)2+ Ag(NH3)+ + NH3, k1 = 1.4 ´ 10–4 M
Ag(NH3)+ Ag+ + NH3, k2 = 4.3 ´ 10–4 M
- The temperature of air decreases linearly with altitude in accordance with the equation T = T0 – ah, where a = constant, h = altitude, T0 = temperature at the ground level, T is the temperature at the altitude. Then prove that the barometric relation
ln ln T0 = ln (T0 – ah).
- H2S is bubbled into a 0.2 M NaCN solution which is 0.02 M in each and . Determine which sulphide precipitate first
Given Ksp (Ag2S) = 1 × 10-50 M3
Ksp (CdS) = 7.1 × 10-28 M2
K inst = 1.0 × 10-20+ M2
K inst (CdI4]-2 = 7.8 × 10-18 M4
- Identify A to E in the following
- Compound (A), M.F C6H12O2 reduces ammonical silver nitrate to metallic silver and looses its optical activity on strong heating yielding (B), C6H10O which readily reacts with dilute KMnO4. (A) on oxidation with alkaline KMnO4 gives (C) having M.F C6H10O3 which decarboxylates readily on heating to 3-pentanone. The compound (A) can be synthesized from a carbonyl compound having M.F. C3H6O on treatment with dilute NaOH. Oxidation of (B) with ammonical silver nitrate followed by acidification gives (D). (D) forms a derivative (E) with SOCl2 which on reaction with H3CNHCH2CH3 yields (F). Identify (A) to (F) giving proper reaction sequences. What is the name reaction involved in the conversion of C3H6O to (A)?
- A compound ‘A’ C13H10BrNO, which is sparingly soluble in cold water, dissolved on boiling with conc. HCl. When cooled the resulting solution deposited a solid B, C7H6O2, which displaced CO2 from Na2CO3 solution. Basification of the solution which remained yielded a solid C, which contained C = 41.9%, H = 3.5%, Br = 46.5% and N = 8.1%.
Treatment of ice cold solution of C in HCl with NaNO2 followed by Copper (I) bromide gives compound D. The reaction of D with fuming HNO3 and conc. H2SO4 gives only one compound E. Identify A to E with proper reasoning.
- i) A black coloured compound (B) is formed on passing H2S through the solution of a compound (A) in NH4OH.
- ii) (B) on treatment with HCl and KClO3 gives (A)
iii) (A) on treatment with KCN gives a buff coloured ppt. which dissolves in excess of this reagent forming a compound (C).
- iv) The compound (C) is changed into a compound (D) when its aqueous solution is boiled.
- v) The solution of (A) was treated with excess of NaHCO3 and then with Br2 On cooling and shaking for some time, a green colour of compound (E) is formed. No change is observed on heating.
Identify (A) to (E) and give chemical equations for the reaction at steps (i) to (v)
- A white powder (A) on heating gives a colourless gas (B) and a solid (C). The compound (C) assume a yellow colour on heating and changes to white on cooling. If dissolves in dilute acids and the resulting solution gives a white precipitate with K4Fe(CN)6. Further (A) dissolves in dil HCl with the evolution of a gas, which is the same as B, which turns lime water milky. The solution so obtained gives a white precipitate (D) with H2S in the presence of NH4OH. Another portion of the solution gives initially a precipitate (E) with NaOH solution, which dissolves in excess of the base. Identify the compounds (A) to (E)