Naming Covalent Compounds, Acids, and Bases

Transcription

1 Naming Covalent Compounds, Acids, and Bases 1

2 Covalent Compounds Share 2

3 Covalent Compounds Unlike ionic compounds who transfer its electron from one element to another, covalent compounds share their electrons. Covalent compounds can easily be identified because they are made with two non-metals. Therefore, if there aren t any metals in the compounds it must be a covalent compound. 3

4 Covalent Compounds Covalent compounds do not have ions; therefore, the do not carry charges. Instead the elements share the electrons, forming bonds. The electronegativity of each element also plays a big part on the bonding. There are two types of covalent compounds: polar, and non-polar. 4

5 Polarity in Bonds Polarity is determined by the electronegativity of the elements in a compound. If the difference in the electronegativity of two elements in less than 0.5, then it is non-polar. If the difference in the electronegativity is between , then it is polar. Anything greater than that would be considered ionic. 5

6 Electronegativity Chart 6

7 Covalent Compounds Unlike ionic compounds, the ratio between how many of one element will combine with another is not always fixed. For example, in an ionic compound when you mix Na and Cl you will get NaCl, never will it be different. In a covalent compound, however, you may mix C and O and get CO or CO 2. 7

8 How to Name Covalent Compounds In order to distinguish between compounds such as CO and CO 2 prefixes needs to be used to distinguish the ratio between the two elements. The prefixes that used are: 8

9 Examples The first element s name doesn t change, unless you need to use a prefix to inform that there are more than one of that element. You still need to add ide at the end of the last element. CO would be named carbon monoxide. CO 2 would be named carbon dioxide. N 2 O would be named dinitrogen monoxide. 9

10 Practice Problems: Name the following compounds: N 2 O 5 BrF 5 SiCl 4 N 2 O 3 NO H 2 O Answers: Dinitrogen pentoxide Bromine pentafloride Dinitrogen trioxide Nitrogen monoxide Water 10

11 Acids and Bases Acids are aqueous solutions that donates a proton, H +, when mixed with other compounds or solutions. Bases are aqueous solution that accepts a proton, H +, when mixed with other compounds or solution. When you mix an acid and a base water is formed, because bases have an OH - that accepts the H + from the acid and form H 2 O. 11

12 Acids There are two types of acids: binary acids and ternary/terciary acids. As the names suggests binary acids are acids that contain two elements. One of which is hydrogen. Ternary acids have more than two elements. Usually a mixture of hydrogen and a polyatomic ion. 12

13 Binary Acids Binary acids always have he prefix hydro- in front of the name. Acids must always be in aqueous form, if it is in solid form than it is named as a regular compound. The second element s ending is charged to ic when naming the acid. The word acid must follow the name of the compound. For example: HBr (aq) will be named hydrobromic acid. 13

14 Naming Binary Acids 14

15 Terciary Acids When naming an acid that contains a polyatomic ion in it you do not add the prefix hydro-. HINT: Whenever you see the word HYDRO you must have a binary acid. If the polyatomic ion s ending is ate it then becomes ic. If the polyatomic ion s ending is ite then it becomes ous. 15

16 Naming Ternary Acids 16

17 Group 7 Ternary Acid Notice how in the previous chart some of them had prefixes. Chlorine, bromine, and iodine can combine with up to 4 oxygens to form a polyatomic ion. In order to distinguish between the four ions we need to add prefixes. 17

18 Group 7 Ternary Acid The two with the highest number of oxygen ClO 3- and ClO 4- carry the ending ate, but the one with the highest of all carry the prefix per-. Therefore, ClO 4- is named perchlorate and ClO 3- is named chlorate. 18

19 Group 7 Ternary Acid Likewise, the two with the lowest number of oxygen ClO 2- and ClO - carry the ending ite, but the one with the least oxygen carry the prefix hypo-. Therefore, ClO 2- is named chlorite and ClO - is named hypochlorite. 19

20 Naming Ternary Acid Containing Group 7 Polyatomic Compounds Other than including the prefixes, naming these compound when they are mixed with hydrogen in aqueous form is the same as any other ternary acid. 20