State which of the following ions or radiacals given below of non metallic elements exhibit valencey: `1^(-),2^(-)` & `3^(-)` -a] Chloride b] Bromide c] Iodide d] Nitrate e] Hydroxide I] Sulphide m] Sulphite n] Sulphate o] Carbonate p] Dichromate q] Zincate r] Plumbite s] Phosphate t] Nitride-[Write each ion or radical with the correct valency]

Write the chemical formula of the following compounds in a step by step manner a. Potassium choride b. sodium bromide c. Potassium nitrate d. Calcium hydroxide e. Calcium bicarbonate f. Sodium bisulphate g. Potassium sulphate h. Zinc hydroxide i. Potassium permanganate j. Potassium dichromate k. Aluminium hydroxide l. Magnesium nitride m. sodium zincate n. copper II oxide o. Copper (I) sulphide p. Iron [III] chloride q. Iron [II] hyrdoxide r] Iron [III] sulphide s. Iron [III] oxide.

Certain metals exbibit variable valencies which include valencies 1^(+),2^(+),3^(+) & 4^(+) . State the variable valency of the following metals -a] Copper b] Silver c] Mercury d] Iron e] Tin f] Lead-[Write each symbol with the variable valency]

(a) Complete the following chemical equations for reactions : (i) MnO_(4(aq))^(-) + S_(2)O_(3(aq))^(2-) + H_(2)O_((l)) to (ii) Cr_(2)O_(7 (aq))^(2-) + H_(2)S_((g)) + H_((aq))^(+) to (b) Give an explanation for each of the following observations : (i) The gradual decrease in size (actinoid contraction) from element to element is greater among the actinoids than that among the lanthanoids (lanthanoid contraction.) (ii) The greatest number of oxidation states are exhibited by the members in the middle of a transition series. (iii) With the same d-orbitals configuration (d^(4)) Cr^(2+) ion is a reducing agent but Mn^(3+) ion is an oxidising agent .

From the list of characteristics given below, select the five which are relevant to non-metals and their compounds : A Ductile B Conduct electricity C Brittle D Acidic oxides E Basic oxides F Discharged at anode G Discharged at cathode H lonic chlorides 1 Covalent chlorides J Reaction with dilute sulphuric acid yields hydrogen K 1, 2 or 3 valence electrons L 5, 6 or 7 valence electrons (Write the five letters corresponding to the correct characteristics)

Explain with the help of - electron dot diagrams - the formation of the following molecules, stating the valency of each element involved. [a] Hydrogen [b] Chlorine [c] Oxygen [d] Nitrogen [e] Water [f] Methane [ g] Carbon tetrachloride [h] Ammonia [i] Carbon dioxide [at.nos. H = 1, C = 6, N = 7, O = 8, Cl = 17].

Write balanced redox reactions for each of the following reactions: (a) Potassium dichromate (K_(2)Cr_(2)O_(7)) reacts with hydroiodic acid (HI) to produce potassium iodide, chromium (III) iodide, and solid iodine, I_(2)(s) . (b) A purple solution of aqueous potassium permanganate (KMnO_(4)) reacts with aqueous sodium sulphite (Na_(2)SO_(3)) in basic solution to yield the green magnanate ion (MnO_(4)^(2-)) and sulphate ion (SO_(4)^(2-)) . (c ) Sn^(2+) (aq) reduce I_(4)^(Ө)(aq) to I^(Ө)(aq) and is oxidised to Sn^(4+) . (d) H_(2)O_(2)(aq) oxidises Mn^(2+)(aq) to MnO_(2) in basic medium. (e) H_(2)O_(2)(aq) reduces Cr_(2)O_(7)^(2-) (aq) to green coloured Cr^(3+)(aq) in acidic medium.

According to C.F.T, attraction between the central metal ion and ligands in a complex is purely electrostatic. The transition metal which forms the central atom cation in the complex is regarded as a positive ion. It is surrounded by negative ligands or neutral molecules which have a lone apir of electrons, if the ligand is a neutral molecule such as NH_(3) , the negative and of the dipole in the molecule is directed towards the metal cation. the electrons on the central metal ion are under repulsive forces from those on the ligands. thus the electrons occupy the d-orbitals remain away from the direction of approach ligands. ltBrgt Q. Correct relationship between pairing energy (P) and C.F.S.E. (Delta_(o)) in

State whether each of the following statements are true or false. If the statement is false re-write the given statement correctly: (i) If p={m , n}a n d\ Q={n , m},\ t h e n\ PxxQ={(m , n),\ (n , m)} (ii) If A and B are non empty sets then AxxB is a non empty set of ordered pairs (x , y) such that x in B\ a n d\ y in Adot (iii) If A={1,2},\ B={3,4},\ t h e n\ Axx(Bnnvarphi)=varphidot

Redox reactions play a pivotal role in chemistry and biology. The values standard redox potential (E^(c-)) of two half cell reactions decided which way the reaction is expected to preceed. A simple example is a Daniell cell in which zinc goes into solution and copper sets deposited. Given below are a set of half cell reactions ( acidic medium ) along with their E^(c-)(V with respect to normal hydrogen electrode ) values. Using this data, obtain correct explanations for Question. I_(2)+2e^(-) rarr 2I^(c-)," "E^(c-)=0.54 Cl_(2)+2e^(-) rarr 2Cl^(c-), " "E^(c-)=1.36 Mn^(3+)+e^(-) rarr Mn^(2+), " "E^(c-)=1.50 Fe^(3+)+e^(-) rarr Fe^(2+)," "E^(c-)=0.77 O_(2)+4H^(o+)+4e^(-) rarr 2H_(2)O, " "E^(c-)=1.23 Among the following, identify the correct statement. (a)Chloride ion is oxidized by O_(2) . (b) Fe^(2+) is oxidized by iodine. (c)Iodide ion is oxidized by chlorine (d) Mn^(2+) is oxidized by chlorine.

The questions below refer to the following salt solutions listed A to F:- A: Copper nitrate B: Iron [II] sulphate C: Iron [III] chloride D: Lead nitrate E: Magnesium sulphate F: Zinc chloride. i) Which two solutions will give a white precipitate when treated with dilute hydrochloric acid followed by barium chloride solution. [i.e. white ppt. insoluble in dil. HCI] ii) Which two solutions will give a white ppt. when treated with dil. HNO_3 & AgNO_3 soln. iii) Which soln. will give a white ppt. when either dil. HCl or dil. H_2SO_4 , is added to it. iv) Which soln. becomes a deep/inky blue colour when excess of ammonium hydroxide is added to it. v) Which solution gives a white precipitate with excess ammonium hydroxide solution.