See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

H S gas passed in all the following test tube having one of the ions 2 2 2 2 Zn ,Ni ,Mn and Cd     so that that precipitation is observed. Which is correct match Yellow Black White Buff (A) Ni – yellow (B) Cd - buff (C) Zn - white (D) Mn - black Ans. C Sol. NiS – black, CdS – yellow, Zn – white, Mns – buff. 41. Select the incorrect observation(s) for a 8.21 litre container, filled with 2 moles of Ar at 300 K (A) It has pressure 6 atm if Ar behaves as an ideal gas and walls of container are rigid. (B) If the container is opened at one side, moles of gas diffused from container when heated to 400 K is 1.75 if Ar behaves as an ideal gas. (C) If Ar behaves as a non-ideal gas and volume of gas is negligible compared to the total volume occupied by gas, it would have pressure greater than 6 atm. (D) If it is in closed non-rigid (like thin balloon) container and Ar gas behaves an ideal gas, its volume increases to 16.42 lit on heating to 600 K. Ans. C Sol. 2 2 an P V nRT V         2 2 nRT an P V V   Hence, would have pressure lesser than 6 atm. 42. Which of the following statement is incorrect? (A) In the metallurgy of aluminium, purified 2 3 2 Al O is mixed with CaF which lowers the melting point of the mixture and brings conductivity. AITS-PT-III-PCM-JEE(Main)/22 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com 23 (B) In the metallurgy of gold by forest cyanide process Zn acts as a reducing agent. (C) Van Arkel method is used for refining Zirconium. (D) Pig iron obtained from blast furnace contains about 1% carbon and many impurities in smaller amount. Ans. D Sol. Pig iron contains about 4% carbon. 43. Which of the following statement is incorrect regarding complex   2 2 5 Fe H O NO      ? (A) The oxidation state of iron in the complex is +2. (B) Complex is formed during the brown ring test for nitrate ion. (C) The colour is because of charge transfer. (D) There are three unpaired electrons so that its magnetic moment is 3.87 BM. Ans. A Sol. NO transfer its electron to 2 Fe  so that iron exists as Fe(I) and NO as NO. 44. Which of the following statement is correct? (A) Photochemical smog occurs in a day time while classical smog occurs in the morning hours. (B) Classical smog has an oxidizing character whereas the photochemical smog is reducing in character (C) During formation of smog, the level of ozone in the atmosphere goes down. (D) Classical smog is good for health but not photochemical smog. Ans. C Sol. Conceptual 45. Select the incorrect statement (A) Silicon carbide is an example of network solid. (B) The number of atoms present in one unit cell of body centred cubic is two. (C) In face centred cubic unit cell two tetrahedral voids are present at each body diagonal of the cube. (D) Coordination number of Na with respect to Na in NaCl is 6. Ans. D AITS-PT-III-PCM-JEE(Main)/22 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com 24 Sol. Coordination number of Na with respect to Na in NaCl lattice is 12. 46. Which of the following does not give precipitate with 2 4 K CrO ? (A) Ag (B) 2 Pb  (C) 2 Ca  (D) 2 Sr  Ans. C