Worksheet #6. Covalent (Molecular) Compounds 1. What happens when a covalent bond is formed? What keeps the species together in a covalent bond?

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1 Worksheet #6 Covalent (Molecular) Compounds 1. What happens when a covalent bond is formed? What keeps the species together in a covalent bond? Binary Compounds with Hydrogen 2. Write correct names for the following compounds: a) HCl; b) H 2 S; c) HBr; d) HF; e) H 2 Se. 3. Write correct formulas for the following compounds: a) hydrogen iodide; b) hydrogen fluoride; c) hydrogen sulfide; d) hydrogen selenide. Naming Covalent Compounds 4. Write correct names for the following compounds: a) CS 2 ; b) SiF 4 ; c) ClF 5 ; d) SO 2 ; e) N 2 O 5 ; f) PCl 5 ; g) SiO 2 ; h) Cl 2 O 6 ; i) S 2 Cl 2 ; j) SF Write correct formulas for the compounds: a) tricarbon disulfide; b) bromine trichloride; c) dinitrogen trioxide; d) tetraphosphorous trisulfide; e) sulfur hexafluoride; f) iodine trichloride; g) disulfur decafluoride; h) phosphorous pentafluoride; i) chlorine monoxide; j) dinitrogen monoxide. Naming Acids 6. Write correct names for the following compounds: a) H 2 SO 4 ; b) HNO 3 ; c) HClO; d) HClO 4 ; e) CH 3 CO 2 H. 7. Write correct formulas for the following compounds: a) hydrocyanic acid; b) phosphoric acid; c) chlorous acid; d) carbonic acid; e) sulfurous acid; f) chromic acid. Write the symbol for the following elements. 1. calcium 2. iodine 3. antimony Chapter 9 Simple Inorganic Nomenclature Section A Name the following compounds. 7. NaOH 8. NH 4 CN 9. Fe 2 S 3 Section C Give the formulas for the following compounds. 10. ammonium hydroxide 11. calcium sulfide 12. sodium peroxide

2 Name the following compounds. (Use the Greek count of atoms.) 13. TiCl PbO BF 3 Give the formulas for the following compounds. 16. phosphorus pentoxide 17. silicon tetrachloride 18. sulfur trioxide Name the following oxyacids. 19. HNO H 2 CrO HlO 4 Section D Give the formulas for the following acids. (Note: Some are unstable or don t exist.) 22. phosphorous acid 23. selenic acid 24. chlorous acid Name the following anions. 25. NO SO Cr 2 O 7 Section E Give formulas for the following anions. Show the charge. 28. sulfite 29. chlorite 30. acetate Name the following compounds. 31. Ca 3 (PO 4 ) Al(ClO 3 ) CuSO 4 Section F Write the formulas for the following compounds. 34. sodium dichromate 35. copper(ii) nitrate 36. tin(ii) phosphate

3 Answers to Worksheet #6 Covalent (Molecular) Compounds 1. When a covalent bond is formed, nonmetals share electrons. The electrons act as glue to keep the atoms together. Binary Compounds with Hydrogen When naming binary (two elements, here H + 1 other element) compounds containing hydrogen and another nonmetal, name the hydrogen first, and then name the nonmetal as if it were an anion. In other words, change its ending to ide. When making formulas from names, assume that hydrogen has a +1 charge and give the other nonmetal the charge it would normally get. Remember to balance the charges so that the net charge is zero. 2. a) hydrogen chloride; b) hydrogen sulfide; c) hydrogen bromide; d) hydrogen fluoride; e) hydrogen selenide. 3. a) HI; b) HF; c) H 2 S; d) H 2 Se. Naming Covalent Compounds Name the element with the lowest group number first (exception: If a compound contains only a halogen and oxygen, name the halogen first). The lowest group number element keeps its name. If there is more than one of the lower group element, use the prefixes below, which you should memorized (do not use mono). The higher group number element changes its ending to ide. Always use the prefixes for the higher group number element. Example: CO 2. C is the lower group number, so it will be named first and will keep its name. There is only one of it, so a prefix will not be used. O is the higher group number so it will be named second and the prefix di will be used. CO 2 is carbon dioxide. To write formulas from names, write the elements in order of appearance, and give subscripts equal to the prefixes. Example: dinitrogen tetraoxide. Nitrogen will be written first, and there are two of them. Oxygen will be written second and there are four of them. Dinitrogen tetraoxide is N 2 O 4. Prefixes: 1 = mono; 2 = di; 3 = tri; 4 = tetra; 5 = penta; 6 = hexa; 7 = hepta; 8 = octa; 9 = nona; 10 = deca. 4. a) carbon disulfide; b) silicon tetrafluoride; c) chlorine pentafluoride; d) sulfur dioxide; e) dinitrogen pentoxide; f) phosphorous pentachloride; g) silicon dioxide; h) dichlorine hexoxide; i) disulfur dichloride; j) sulfur tetrafluoride. 5. a) C 3 S 2 ; b) BrCl 3 ; c) N 2 O 3 ; d) P 4 S 3 ; e) SF 6 ; f) ICl 3 ; g) S 2 F 10 ; h) PF 5 ; i) ClO; j) N 2 O.

4 Naming Acids Naming Polyatomic Acids: Acids containing a polyatomic ion are named according to the name of the polyatomic ion. If the polyatomic ion s name ends in ite change it to ous and put the second word acid. (Example: HNO 2 NO 2 is nitrite, so the name will be nitrous acid.) If the polyatomic ion s name ends in ate change it to ic and put the second word acid (remember: I ate an icky bug). (Example: HNO 3 NO 3 is nitrate, so the name will be nitric acid.). The only exception to this is hydrocyanic acid, HCN, which gets the prefix hydro along with the ending change. To write formulas from names, balance the charge of the polyatomic ion with H +, remembering to always write the H first. So, chloric acid: the ending is ic, so the polyatomic ion is chlorate, ClO 3. One H + is needed to balance the 1 charge on chlorate, so chloric acid is HClO a) sulfuric acid; b) nitric acid; c) hypochlorous acid; d) perchloric acid; e) acetic acid 7. a) HCN; b) H 3 PO 4 ; c) HClO 2 ; d) H 2 CO 3 ; e) H 2 SO 3 ; f) H 2 CrO Ca 2. l 3. Sb Answers to Chapter 9 Simple Inorganic Nomenclature Section A Section C 7. sodium hydroxide 8. ammonium cyanide 9. iron(iii) sulfide (or ferric sulfide) 10. NH 4 OH 11. CaS 12. Na 2 O titanium tetrachloride 14. lead dioxide 15. boron trifluoride 16. P 2 O SiCl SO 3

5 19. nitrous acid 20. chromic acid 21. periodic acid Section D 22. H 3 PO H 2 SeO HClO nitrate 26. sulfate 27. dichromate Section E 28. SO ClO C 2 H 3 O 2 Section F 31. calcium phosphate 32. aluminum chlorate 33. copper(ii) sulfate (or cupric sulfate) 34. Na 2 Cr 2 O Cu(NO 3 ) Sn 3 (PO 4 ) 2