The rate of first order reaction is 0.04 mol L^-1s^-1 at 10 min and 0.03 mol L^-1s^-1 at 20 min after initiation. Thus, find the half-life of the reaction.

(i) What type of deviation is shown by a mixture of ethanol and acetone? Give reason.
(ii) A solution of glucose (molar mass = 180 g mol^-1) in water is labelled as 10 % (by mass). What would be the molality and molarity of the solution?
(Density of solution = 1.2 g mL^-1)

(a) When 2.56 g of sulphur was dissolved in 100 g of CS₂, the freezing point lowered by 0.383 K. Calculate the formula of sulphur (S_X). (K_f for CS₂ = 3.83 K kg mol^-1, Atomic mass of sulphur = 32 g mol^-1).
(b) Blood cells are isotonic with 0.9 % sodium chloride solution. What happens if we place blood cells in a solution containing;
(i) 1.2 % sodium chloride solution?
(ii) 0.4% sodium chloride solution?

The half time of first order decomposition of nitramide is 2.1 hour at 15^oC. NH₂NO₂(aq) \(\longrightarrow\) N₂O(g) + H₂O (I) 
If 6.2 g of MH₂NO₂ is allowed to decompose, calculate
(i) time taken for NH₂NO₂ to decompose 99% and
(ii) volume of dry N₂O produced at this point, measured at STP.

The energy change accompanying the equilibrium reaction A \(\rightleftharpoons \) B is -33.0 kJ mol-1. Calculate
(i) Equilibrium constant K_c for the reaction at 300 K
(ii) Energy of activation forward and backward reaction (E_f and E_b) at 300 K. Given that Ef and Assume that pre-exponential factor is same for forward and backward reaction.

The volume of nitrogen gas v_m (measured at S.T.P) required to cover a sample of silica gel with a mono - molecular layer is 129 cm³g^-1 of gel. Calculate the surface area per gram of the gel if each nitrogen molecule occupies \(16.2\times { 10 }^{ -20 }{ m }^{ 2 }\).

On heating compound (A) gives a gas (B) which is a constituent of air.  This gas when treated with 3 mol of hydrogen (H₂) in the presence of a catalyst gives another gas (C) Which is basic in nature.  Gas C on further oxidation in moist condition gives a compound (D) which is a part of acid rain.  Identify compound (A) to (D) and also give necessary equations of all the steps involved.

(a) In which of the following does adsorption take place and why?
(i) Silica gel placed in the atmosphere saturated with water.
(ii) Anhydrous CaCl₂ placed in the atmosphere saturated with water.
(b) How does BF₃ act as a catalyst in industrial process?
(c) Give an example of shape-selective catalysis.

Action of soap is due to emulsification and micelle formation. Comment.

Vapour pressure of pure benzene at a certain temperature is 640 mm Hg. A non-volatile non-electrolyte solid weighing 2.175g is added to 39.0 of benzene. The vapour pressure of solution is 600 mm Hg. What is the molecular mass of solid substance? (65.9g mol^-1).

The degree of dissociation of Ca(NO₃ )₂ in dilute solution aqueous solution containing 7.0g of the solute per 100g of water at 100⁰ C is 70 percent. If the vapour pressure of water at 100⁰ C is 760mm, calculate the vapour pressure of the solution. (746.02mm).

What is meant by positive and negative deviations from Raoult's law and how is the sign of \(\triangle_{mix}\)H related to positive and negative deviations from Raoult's law?

(i) Why does a solution of chloroform and acetone show negative deviation from Raoult's law?
(ii) State how the vapour pressure of a solvent is affected, when a non-volatile solute is dissolved in it?
(iii) A solution of glucose (C₆H₁₂O₆) in water is labelled as 10%by weight. What would be the molality of the solution? (Molar mass of glucose = 180g mol ^-1) 

(i) Two liquids X and Y boil at 100°C and 120°C respectively. Which of them has higher vapour pressure at 50°C and why?
(ii) Calculate the boiling point of a solution prepared by adding 15.00 g of NaCI to 250 g water. (K_b for water = 0.512 K kg mol^-1; molar mass of NaCI = 58.44g)
(iii) Calculate the lowering of vapour pressure for 0.1 m aqueous solution of non -electrolyte at 75°C. (\(\triangle\)H = 9.720 K cal mol^-1, P₂ = 742.96 torr)

2 beakers A and B contain 1 M ZnSO₄ solution. To A , Strip of Mg is dipped, while in B, A zinc rod is put. If both are connected to a standard hydrogen electrode, which cell would show a deflection? Explain with suitable reason.

(i) What is limiting molar conductivity? Why there is steep rise in the molar conductivity of a weak electrolyte on dilution?
(ii) Calculate the emf of the following cell at 298K:
Mg(s) I Mg²⁺(0.1M)|| Cu²⁺(1.0 X 10^-3 M) I Cu(s) [Given= E^ocell = 2.71 V ]

The conductivity of sodium chloride at 298 K has been determined at different concentrations and the
results are given below.

Calculate Λ_m for all concentrations and draw a plot between Λ_m and C^1/2. Find the value of ⋀⁰_m.

Calculate the equilibrium constant for the reaction.
2Fe³⁺+ 3I^- \( \rightleftharpoons \)2Fe²⁺+ I^3-
The standard reduction potential in acidic condition is 0.78V and 0.54 V, respectively, for Fe³⁺/ Fe²⁺ and I₃^-/ I couples.

Write the nernst equation and the e.m.f of the following cells at 298 K :
(i) \(Sn(s)|{ Sn }^{ 2+ }(0.050M)||{ H }^{ + }(0.020M)|{ H }_{ 2 }(g)(1bar)|Pt(s)\)
(ii) \(Pt(s)|{ Br }_{ 2 }(l)|{ Br }^{ - }(0.010M)|{ H }^{ + }(0.030M)|{ H }_{ 2 }(g)(1bar)|Pt(s)\)

²³⁸₉₂U  changes to ²⁰⁶₉₂Pb by successive radioactive decay. A sample of uranium was analysed and found to contain 1.0 g of ²³⁸Uand 0.1 g of  ²⁰⁶Pb had accumulated due to decay of ²³⁸U, find out the age of ore. (Half-life of ²³⁸U = 4.5x 10⁹ years)

(i) How is chlorine produced by electrolytic method?
(ii) How can we get chlorides of noble metals?
(iii) Write the different oxoacids of chlorine in the increasing order of their oxidising power.
(iv) Which noble gas is used in atomic reactor?
(v) What is the oxidation state and bond angle of Xe inXeF₂?

Explain giving reason:
(a) The enthalpies of atomisation of the transition metals are high.
(b) Transition metals and many of their compounds show paramagnetic behaviour.
(c) The transition metals generally form coloured compounds.
(d) transition metals and their many compounds act as good catalyst.

Write down the number of 3d electrons in each of the following ions: Ti²⁺, V²⁺, Cr³⁺, Mn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺ and Cu²⁺. Indicate how would you expect the five 3d orbitals to be occupied for these hydrated ions (octahedral).

The elements of 3d transition series are given as:
8c Ti V Cr Mn Fe Co Ni Cu Zn
Answer the following:
(i) Write the element which shows maximum number of oxidation states. Give reason.
(ii) Which element has the highest melting point?
(iii) Which element shows only +3 oxidation state?
(iv) Which element is a strong oxidising agent in +3 oxidation state and why?

Nuclear power station consists of nuclear reactor, in which a controlled chain reaction involving nuclear fission occurs using either U or Pu as fuel in reactor. The heat produced is extracted from the reactor and this heat is used to generate steam which drives a turbine and produces electricity. U or Pu can also be used in making atom bombs. The subcritical mass of U or Pu is carried out in aeroplanes and combine them to give a critical mass when dropped over the target. It leads to uncontrolled chain reaction which produces tremendous amount of energy and lot of destruction.Plutonium bomb was dropped over Hiroshima and Nagasaki, Japan in world War II which caused lot of destruction.
Answer the following questions.
(i) Should we use U and Pu for making atom bombs?
(ii) What is the long term disadvantages of nuclear radiation?
(iii) Why is U-235 used in nuclear reactor?
(iv) Why are breeder reactors more useful?

(i) (a) How is the variability in oxidation states of transition metals different from that of the p-block elements?
(b) Out of Cu⁺ and Cu²⁺, which ion is unstable in aqueous solution and why?
(c) Orange colour of Cr₂O₇^2- ion changes to yellow when treated with, an alkali. Why?
(ii) Chemistry of actinoids is complicated as compared to lanthanoids. Give two reasons.

Account for the following.
(i) Mn²⁺ is more stable than Fe²⁺ towards oxidation to +3 state.
(ii) The enthalpy of atomisation is lowest for Zn in 3d-series of the transition elements.
(iii) Identify the metal in M03F and justify your answer.
(iv) The E⁰ value for the Mn³⁺ / Mn²⁺ couple is much more positive than that for Cr³⁺ /Cr²⁺ couple. 
(v) Transition metals form a large number of complexes.