Title: Chem Review 4 PART 1 TOPIC: TYPES OF BONDS. EQ: What is an Ionic Bond?

Transcription

1 Title: Chem Review 4 PART 1 TOPIC: TYPES OF BONDS EQ: What is an Ionic Bond?

2 Title and Highlight Topic: EQ: Date Reflect Question: Reflect on the material by asking a question (its not suppose to be answered from notes) NOTES: Write out the notes from my website. Use different types of note-taking methods to help you recall info (different color pens/highlighters, bullets, etc) When I lecture we will add more info, so leave spaces in your notes DRAW ANY PICTURES, FIGURES, AND WRITE OUT ANY PRACTICE PROBLEMS/QUESTIONS. WE WILL ANSWER THEM TOGETHER. So LEAVE SPACES SO WE CAN ANSWER QUES. Summary (end of notes) : 1-2 Sentences of what you learned

3 A few of the substances we encounter in everyday life are elements. Majority are compounds or molecules. In a compound, the elements combine in fixed, definite proportions. This is known as the Law of Constant Composition.

4 A chemical formula indicates the elements present in a compound and the # of atoms of each. For example, H 2 O is the chemical formula for water; it indicates that water consists of H and O atoms in a 2:1 ratio. The formula contains the symbol for each element with subscripts (little # s) indicating the number of atoms of that element. (don t write 1 s). H 2 O 1 = H 2 O

5 Common chemical formulas include: CO for carbon monoxide (1:1 ratio) CO 2 for carbon dioxide (1:2 ratio). C 12 H 22 O 11 for sugar (sucrose) (12:22:11 ratio). If subscripts change, then the formula no longer is that compound. (Muy importante) H 2 O vs. H 2 O 2

6 1. Chemical formulas list the most metallic elements first. Remember - Metals are on the left side of the P.T. and nonmetals on the upper right side. The formula for table salt is NaCl, not ClNa. 2. LEARN: In compounds that do not include a metal, the more metal-like element is listed first. (closest nonmetal to the staircase on P.T.)

7 3. LEARN: Within a group in P.T., elements toward the bottom are more metal-like than elements toward the top. We write SO 2 not O 2 S.

8 The specific order for listing nonmetal elements in a chemical formula is shown in Table 5.1

9 An empirical formula (e.f.) gives the relative number of atoms of each element in a compound. A molecular formula (m.f.)gives the actual number of atoms of each element in a molecule of the compound. For example, the m.f. for hydrogen peroxide is H 2 O 2, and its e.f. is HO. The molecular formula is always a whole number multiple of the empirical formula.

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11 2 types of Compounds ionic bonds molecular bonds (ch 5.8) (M + NM) (NM + NM) (M + PA)

12 ionic bond electrical attraction between ions (charged atoms: cations and anions); e- are taken by one atom and given to another atom (like a magnet). Ionic Compounds Also called Salts ****Ionic bonding only 2 types (sometimes 3 - rare) 1 Metal (cation) + 1 Nonmetal (anion) or 1 Metal (cation) + 1 Polyatomic (anion) (see handout) (The charges are hidden to make a neutral compound.)

13 Metals LOSE electrons. become + ions = CATION

14 Nonmetals GAIN electrons from metals become - ions = ANION ending to name changes to -ide

15 Predicting Charges on Ions KNOW THESE!!!! Label this on your PT! Cd +2

16 1 st step in naming an ionic compound be able to identify it as one. (sometimes the hard part) Ionic Compound (I.C.) Lose (+ ions) and gain (- ions) electrons Cation (+ ions) then anion (- ions) 3 types M + NM = binary I.C. (2 elements) M + P.A. = ternary I.C. (more than 2 elements) P.A. + P.A. = ternary I.C.

17 Binary compounds - contain only two different elements. Draw this with notes!!!

18 cations name doesn t change Example: Ba +2 barium ion anions remove the ending and add ide Example: Cl - is not chlorine. chloride ion Naming: Cation (1 st ) then anion (2 nd ) BaCl 2 is barium chloride

19 Element Anion Symbol Anion Name Bromine Br -1 Bromide Chlorine Cl -1 Chloride Fluorine F -1 Fluoride Hydrogen H -1 Hydride Iodine I -1 Iodide Nitrogen N -3 Nitride Oxygen O -2 Oxide Phosphorus P -3 Phosphide Sulfur S -2 Sulfide

20 I will give you a list of PA s!!!

21 Some ionic compounds contain polyatomic ions (ions that are themselves composed of a group of atoms with an overall charge).

22 Many polyatomic ions are oxyanions, anions containing oxygen. If there are two ions in the series, the one with more oxygen atoms is given the ending - ate and the one with fewer is given the ending -ite. (BOTH SAME CHARGE!!) NO 3 nitrate SO 4 2 sulfate NO 2 nitrite SO 3 2 sulfite

23 If there are more than two ions in the series, then the prefixes hypo-, meaning less than, and per-, meaning more than, are used. ClO hypochlorite BrO hypobromite IO hypoiodite ClO 2 chlorite BrO 2 bromite IO 2 iodite ClO 3 chlorate BrO 3 bromate IO 3 iodate ClO 4 perchlorate BrO 4 perbromate IO 4 periodate

24 Writing Formulas for Ionic Compounds Step 1 write cation (metal) then polyatomic Step 2 Charges have to equal zero!!! Cross the charges if they don t balance out. Step 3-- Use parentheses around polyatomic ion Practice Problems: Write the formula for each ionic compound. copper(ii) bromide Cu +2 Br -1 = CuBr 2 (don t show 1 s) aluminum nitrite Al +3 NO 2-1 = Al(NO 2 ) 3 barium hydrogen carbonate Ba +2 HCO 3-1 = Ba(HCO 3 ) 2

25 1. aluminum nitrate 2. copper(ii) nitrate 3. Iron (III) hydroxide 4. Tin(IV) hydroxide

26 Underlined letter = starting element symbol of the polyatomic # consonants = # of oxygen atoms # vowels = # negative charge on the ion

27 use different colors Nick the Camel ate a Creamy Clam for Supper in Phoenix. Manly Brad had an Itch and took Aspirin.

28 Nick Underlined letter = starting element symbol of the polyatomic # consonants = # of oxygen atoms # vowels = # negative charge on the ion N 3 consonants = O 3 1 vowel = - 1 NO 3-1

29 Title: Chem Review 4 PART 2 TOPIC: TYPES OF BONDS EQ: What is the difference bewteeen Molecular Bonds and Acids?

30 Ionic Covalent (molecular) Metals & Nonmetals Only nonmetals lose/gain e- share e-

31 The first step in naming a molecular compound is identifying it as one. Remember - all molecular compounds form from two nonmetals. (no metals) Use PREFIXES - indicate the # atoms in the compound. Draw this with notes

32 Most of OChem!!! Prefixes in Molecular Compounds Number of atoms Prefix Number of atoms Prefix 1 mono- 6 hexa- 2 di- 7 hepta- 3 tri- 8 octa- 4 tetra- 9 nona- 5 penta- 10 deca-

33 Write the formula for dihydrogen monoxide? Anyone want a cold glass of dihydrogen monoxide?

34 Formula Common Name Molecular compounds name H 2 0 Water Dihydrogen monoxide NH 3 Ammonia Nitrogen trihydride

35 1. If there is only one atom of the first element, the prefix mono- is NOT WRITTEN. CO 2 mono carbon di- ox -ide The full name is carbon dioxide.

36 2. The compound N 2 O also called laughing gas, is named according to the first element, nitrogen, with prefix di-, followed by the second element, prefixed by mono-, and the oxide. dinitrogen monooxide (Wrong!!) HOWEVER. Since mono- ends with a vowel and oxide begins with a vowel, an o is dropped and the two are combined as monoxide. The entire name is dinitrogen monoxide.

37 3. (Rule only for oxygen) drop one of the o Do not follow this rule for other elements. Examples: triiodide or tetraarsenide

38 Practice Problem #3 a. P 2 O 5 b. SO 2 c. IF 7

39 Practice Problem #4: Name the following molecules. a. N 2 O 5 b. CO c. Cl 4 F 7 d. SO 3

40 Practice Problem #5: Write the formula for each molecule. a. nitrogen monoxide b. carbon tetrachloride c. diphosphorus nonaoxide

41 Acids are MOLECULAR compounds (share e-) that form ions when dissolved in water. Composed of hydrogen, written first in their formula, and one or more nonmetals, written second. Categorize acids into two groups: binary acids & oxyacids. Make flowchart for the notes!!!

42 H and 1 nonmetal H and polyatomic Draw this with notes

43 Binary acids are composed of hydrogen and a nonmetal. The names for binary acids have the following form: Draw this with notes

44 HCl(aq) is hydrochloric acid. HBr(aq) is hydrobromic acid. HCl(g) refers to hydrogen chloride molecules in the gas phase, and not to the acid. Give the name of H 2 S(aq) and H 3 P. (Be careful of spelling)

45 2. Naming Oxyacids Draw this with notes

46 Oxyacids are acids that contain oxyanions (polyatomic with oxygen) The number of H + ions depends on the charge of the oxyanion, so that the formula is always charge-neutral (criss-cross).

47 2. If the acid s name ends with -ic without the hydro- prefix, the name of the anion used ends in. -ate Therefore, it is an oxy- acid. Examples: perchloric acid = acetic acid = 3. If the acid s name ends with, -ous the name of the anion used ends in. -ite (It s is also an oxy-acid.) Examples: hypochlorous acid = nitrous acid = sulfurous acid =

48 Naming Oxy-Acids 1. If the name of (X) ends in ate -ic acid 2. If the name of (X) ends in ite -ous acid Practice Problems: Name these acids. H 2 SO 4 H 3 PO 3 HNO 3 H 2 CO 3 HC 2 H 3 O 2 HClO 2 Naming Binary Acids 2 elements If the name of (X) ends in ide hydro- -ic acid Practice Problems: Name these acids. H 2 S HCl HF

49 Draw