Question

Name: DUITE SIT Homework 10 - Ch. 21-23 (A) B2H6 (8) NH3 (1) Cah2 (D) HCI 12. In K[Cu(CN)2], how many 3d electrons does the copper ion have? (A) 4 (B) 5 (C) 8 (D) 10 (E) 12 13. Carbon dioxide is used in all of the following ways except: A) to provide the "bite in soft drinks C) as a refrigerant B) in fire extinguishers D) All of these 14. Nitric acid and sulfuric acid are both powerful oxidizing agents because (A) the central elements (N and Share in high oxidation states Cl these elements are very store B) the central elements (N and S) have low oxidation states D) All of these 15. The halogens are: A) strong acids B) oxidizing agents C) reducing agents D) not very reactive 16. Which form of hydrogen is used in research because of its radioactivity? A) hydrogen(1H) B) deuterium(2H) C) tritium(3) D) none of the above 17. Which of the following are allotropes of phosphorous? (1) P4; (1) P406; (II) P4010, (IV) (P4) (A) il and ill B) I and II C) I and IV D) I and IV 18. Which of the following is a list of LIH, CH4, and NH3 in order of decreasing boiling points? A) UH > CH4 > NH3 c) LIH > NH3 > CH, B) NH3 > CH4 > LiH DỊ NHU > LIH > CH4 19. Sodium hypochlorite is used A) as an oxidizer in rocket fuels. C) in the manufacture of steel. B) as a bleaching agent. D) in the chemical analysis of agricultural pesticides. 20. What is the most prominent element in the universe? A) Oxygen B) Nitrogen C) Helium D) Hydrogen 21. The correct chemical formula for tetraamminecopper(II) chloride is: (A) [Cu(NHS).CI C ) [Cu(NH).JCh, E) [Cu(NH)]CL B) [Cu(NH4Cl, D) [Cu(NH)]CI 22. The best name for K[Cr(NH3),C(CN):) is: A) potassium diamminedichlorodicyanochromate(11) C) potassium diamminedichlorochromate(II) cyanide B) potassium diamminedichlorodicyanochromium(Ill) D) potassium diamminedichlorochromatium(1) cyanide 23. Which of the following ligands is most likely to form a high spin octahedral complex with cobalt()?

Answer 1

12. D, In this complex Cu is in the +1 oxidation state, as the total charge of [Cu(CN)₂] is -1 and for each CN the charge is -1(i.e. total -2). Hence Cu is in the +1oxidation state. So the total no of 3d electron in Cu (+1) is 10.

13. D

14. A, An oxidizing agent is a reactant that removes electrons from other reactants during a redox reaction and typically takes these electrons for itself, thus gaining electrons and being reduced. Powerful oxidizing agents are those where the central atom is in high oxidation state so that it can accept electrons easily from other reactants.

15. B, An oxidizing agent is a reactant that removes electrons from other reactants during a redox reaction and typically takes these electrons for itself, thus gaining electrons and being reduced. Similarly, Halogens can accept electrons from other reactants and get reduced to halides.

16. C

17. D

18. C, LiH is predominately an ionic compound whereas CH₄ and NH₃ are predominately covalent in nature. Thus the boiling point of LiH is greater than both CH₄ and NH₃. Among CH₄ and NH₃, the intermolecular attractive forces occurring in, NH₃ are hydrogen bonding and London dispersion forces. The intermolecular attractive forces occurring in, CH₄ are only London dispersion forces. Hydrogen-bonding attractive forces are stronger forces compared to dispersion forces when atoms are in the second period. Therefore, NH₃ has a higher boiling point compared to CH₄.

19. B

20. B

21. B

22. A