State which type of chemical reactions proceed with - a. Evolution of heat energy b. Absorption of heat energy. State in each of the following reactions whether heat is evolved or absorbed - i. Water is added to quicklime ii. Two neutral gases on passage through an electric arc give niric oxide iii. Two neutral gases combine to give - a basic gas.

Give a balanced equation for each of the following types of reaction: A reaction of direct combination i.e. synthesis in which two gases combine to give another gas-which turns lime water milky.

Give two examples each of the following oxides - a. Acidic oxides b. Basic oxides c. Amphoteric oxides d. Neutral oxides. State which of the following oxides i.e. a. to d. - (i) React with water to give a base (ii) React with a base to give salt & water (iii) React with acids & bases to give salt & water.

Write chemical equations for the following reactions: (i) Calcium metal reacts with water. (ii) Cinnabar is heated in the presence of air. (iii) Manganese dioxide is heated with aluminium powder. (b) What are alloys? List two properties of alloys.

Classify the following reactions into- a. Direction combination b. Decomposition c. Displacement d. Double decomposition - The reactions are - i. Zinc hydroxide on heating gives zinc oxide & water ii. Zinc reacts with copper [II] sulphate to give zinc sulphate & copper iii. Zinc sulphate reacts with ammonium hydroxide to give ammonium sulphate & zinc hydroxide iv. Molten zinc at high temperatures, burns in air to give zinc oxide.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case. (a) Iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide. (b) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride. (c) Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine. (d) Ethanol is burnt in air to form carbon dioxide, water and releases heat.

A compound (A) is greenish crystalline salt, which gave the following reactions. (i)Addition of BaCl_(2) solution to the solution of (A) results in the formation of white precipitate (B) which is insoluble in dilute HCl . (ii)On heating (A) , water vapours and two oxides of sulphur (C ) and (D) are liberated leaving a red brown residue (E) . (iii) (E) dissolves in warm concentrated HCl to give a yellow solution (F) . (iv)Solution (F) on treatment with thiocyanate ions gives blood red coloured compound (G) . Identify the compounds from (A) to (G) .

The straight lines in the figure depict the variations in temperature DeltaT as a function of the amount of heat supplied Q is different process involving the change of state of a monoatomic and a diatomic ideal gas . The initial states, ( P,V,T ) of the two gases are the same . Match the processes as described, with the straight lines in the graph as numbered. {:(,"Column-I",,"Column-II"),((A),"Isobaric process of monoatomic gas." ,(p),"1" ),((B),"Isobaric process of diatomic gas" ,(q),"2" ),((C),"Isochoric process of monoatomic gas" ,(r),"Minimum at section B"), ((D),"Isochoric process of diatomic gas" ,(s),"x-axis (i.e.'Q' axis)"):}

Read the following paragraph and answer the questions given below , Stable equilibrium is of various types . Mechanical equilibrium is achieved when all particles are at rest and total potential energy of the system is minimum . At any stage where particles are at rest but the system is not at stable equilibrium as it can reduce its potential energy by reverting to another position, is called metastable equilibrium . Thermal equilibrium is result from the absence of temperature gradients in the system. Chemical equilibrium is obtained when no further reaction occurs between reacting substances, i.e forward and reverse rates of reaction are equal. When steam with solid iron at high temperature Fe_3O_4(s) and hydrogen gas are produced . But the reaction never goes to completion. This is because as the products are formed the reaction proceeds in reverse direction and when rate of reverse reaction is equal to rate of forward reaction , the concentration of reactants and products become constant and equilibrium is reached. When two reactants (A) and (B) are mixed to give products (C) and (D) the concentration quotient (Q) at initial stage of the reaction

Salts M, N, O, P and Q undergo reactiom (i) to (v) respectively. Identify the cation present in these salts on the basis of these reaction. Tabulate your answer in the format given below. 1. When sodium hydroxide solution is added to the salt M, and heated strongly a colourless gas with a pungent smell is evolved which turm red litmus paper blue and gives dense white fumes with a moist glass rod with hydrochloric acid. 2. Addition of dilute hydrochloric acid to a solution of N gives a thick white precipitate which is soluble in hot water. 3. When ammonium hydroxide solution is added to the solution of 0 a light blue precipitate is obtained which is soluble in excess of ammonium hydroxide to form an inteme deep blue solution. 4. When ammonium hydroxide solution is added to the solution of P reddish brown (mustard colour) precipitate is obtained which ,is insoluble even in the excess of ammonium hydroxide solution. 5. When sodium hydroxide solution is added to the solution of Q a which coloured gelatinous precipitate is obtained which is soluble in excess of sodium hydroxide to form a clear solution

A mixture of two salt was treated as follows : i. The mixture was heated with magnanese dioxide and concentrated sulphuric acid , when a yellowish -green gas was liberated. ii. The mixture on heating with sodium hydroxide solution gave a gas which turned red litmus blue iii. Its solution in water gave a blue precipitate with potassium ferricyanide and red colourtion with ammonium thiocynate iv. The mixture was boiled with potassium hydroxide and the librated gas was bubbled through an alkline solution of K_(2)HgI_(4) to give a brown precipitate identify the two salts gives ionic equation for the reaction involved in the tests (i) , (ii) and (iii).