Unit+5+-+Ionic+Bonds

= = =__Ionic Bonds__ Ionic Bonds are bonds between only 2 different elements, when 1 element needs electrons and another element has too many. Think of regular table salt NaCl. Na has a positve charge of +1 and Cl has a negitive charge of -1. Ionic bonds are more about giving and taking and covalent bonds are more about sharing.= =Ionic Bonds follow the octet rule: The valence e- (the e- in the "s" and "p" orbitals) will bond with another atom so that the bond adds up to 8 e-. O (4 v. electrons) + O (4 v. electrons)=
 * 8 electrons = an octet=**

1) Which of the following ions occurs commonly? A. N3+ B. S6+ __C. O2-__ D. Ca+ E. Cl+

//2) Which of the following ions occurs commonly? A. P3+ B. Br7+ C. O6+ __D. Ca2+__ (only one that the element matches its charge) E. K-//


 * 1. Mg = magnesium, F2 = 2 florines = difluoride**

3) The colorless substance, MgF2, is used in the ceramics and glass industry. What is its name? __A. magnesium difluoride__ B. magnesium fluoride C. magnesium(II) fluoride D. monomagnesium difluoride E. none of these choices is correct, since they are all misspelled

4) The compound, BaO, absorbs water and carbon dioxide readily and is used to dry gases and organic solvents. What is its name? __A. barium oxide__ B. barium(II) oxide C. barium monoxide D. baric oxide E. barium peroxide

5) What is the name of Na2O? A. disodium monoxide B. sodium monoxide C. sodium dioxide D. sodium(I) oxide __E. sodium oxide__

6) The substance, CaSe, is used in materials which are electron emitters. What is its name? A. calcium monoselenide B. calcium(II) selenide __C. calcium selenide__ D. calcium(I) selenide E. calcium(II) selenium


 * For identifying ions you just have to look at your PT or your pink sheet. Watch for endings, charges -ate and -ites**

7) Which one of the following combinations of names and formulas of ions is incorrect? __A. O2- oxide__ (Oxygen) B. Al3+ aluminum C. NO3- nitrate D. PO43- phosphate E. CrO42- chromate

8) Which one of the following combinations of names and formulas of ions is incorrect? A. O2- oxide B. Cd2+ cadmium C. ClO3- chlorate D. HCO3- hydrogen carbonate __E. NO2- nitrate__

9) Which one of the following combinations of names and formulas of ions is incorrect? A. Ba2+ barium B. S2- sulfate C. CN- cyanide D. ClO4- perchlorate __E. HCO3- bicarbonate__

10) Which one of the following combinations of names and formulas of ions is incorrect? A. NH4+ ammonium __B. S2- sulfide__ C. CN- cyanide D. S2O32- thiosulfate E. ClO3- perchlorate

//1//1) Zinc acetate is used in preserving wood and in manufacturing glazes for porcelain. What is its formula? A. ZnAc2 B. ZnCH3COO __C. Zn(CH3COO)2__ switch charges D. Zn2CH3COO E. ZnCH3COCH3

12) Silver chloride is used in photographic emulsions. What is its formula? A. Ag2Cl3 B. Ag2Cl C. AgCl3 D. AgCl2 __E. AgCl__

13) Barium sulfate is used in manufacturing photographic paper. What is its formula? __A. BaSO4__ B. Ba(SO4)2 C. Ba2SO4 D. Ba2(SO4)3 E. BaSO3

//14) Sodium peroxide is an oxidizer used to bleach animal and vegetable fibers. What is its formula? A. NaO B. NaO2// //__C. Na2O2__ D. Na2O E. NaH2O2//

15) What is the formula for magnesium sulfide? __A. MgS__ B. MgS2 C. Mg2S D. Mg2S3 E. MgSO4


 * For these equations simpily divide the grams of the Oxy. (8.009) from the total grams of Al4Si4O10(OH)8 (14.35) to find the percent of oxy.**

16) Kaolinite, a clay mineral with the formula Al4Si4O10(OH)8, is used as a filler in slick-paper for magazines and as a raw material for ceramics. Analysis shows that 14.35 g of kaolinite contains 8.009 g of oxygen. Calculate the mass percent of oxygen in kaolinite. A. 1.792 mass % B. 24.80 mass % C. 30.81 mass % D. 34.12 mass % __E. 55.81 mass %__

(total = (x)+ __isotope 2__)**
 * amu = atomic mass unit**
 * Plug the #s into the equation (total = (100-x)___isotope 1_)__

17) Lithium forms compounds which are used in dry cells and storage batteries and in high-temperature lubricants. It has two naturally occurring isotopes, 6Li (isotopic mass = 6.015121 amu) and 7Li (isotopic mass = 7.016003 amu). Lithium has an atomic mass of 6.9409 amu. What is the percent abundance of lithium-6? A. 92.50% __B. 86.66%__ C. 46.16% D. 7.503% E. 6.080%


 * Calculating Molar mass is basically the same as finding the # of grams in a compound: look at your PT to find the grams for each element and add them together.**

18) Ammonium sulfate, (NH4)2SO4, is a fertilizer widely used as a source of nitrogen. Calculate its molecular mass. A. 63.07 amu B. 114.l0 amu C. 118.13 amu D. 128.11 amu __E. 132.13 amu__

19) Sodium chromate is used to protect iron from corrosion and rusting. Determine its molecular mass. A. 261.97 amu B. 238.98 amu __C. 161.97 amu__ D. 138.98 amu E. 74.99 amu


 * Add the grams of Ca(Bo3) to 6 waters**

20) Calculate the molar mass of Ca(BO3)2·6H2O. A. 273.87 g/mol __B. 233.79 g/mo__l C. 183.79 g/mol D. 174.89 g/mol E. 143.71 g/mol

2. Set up a stoich problem (1.72 moles x 62.308 grams / 1 mole) = answer**
 * 1. Find the grams of MgF2 (remember there are 2 Florines)

21) Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride? A. 43.3 g B. 62.3 g C. 74.5 g D. 92.9 g __E. 107 g__


 * Basically the same as the previous problem, but in step 2 you use grams to find moles**

22) Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3. A. 2.377 mol B. 2.146 mol C. 1.105 mol __D. 0.4660 mol__ E. 0.4207 mol

Sorry, this is a long one. Find grams for each element (from PT). Add them together to find total grams. Divide grams of the individual elements by the total to find the % of each element in the compound. Use the desired % (in this case Oxy) and multy. by the sample (29.34 grams). Set up a Stoich problem starting with your new amount of grams (the answer to the previous step), contain avagadro's number (6.022 X 10^23) and the end unit should be atoms. (13.203g x (1 mole / 15.999g) x (6.022 x 10^23 / 1 mole))**
 * Avagadro's number is 6.022 x 10^23 atoms. It stands for the amount of atoms in 1 mole.

23) Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na2SO4. A. 1.244 × 1023 O atoms B. 4.976 × 1023 O atoms C. 2.409 × 1024 O atoms __D. 2.915 × 1024 O atoms__ E. 1.166 × 1025 O atoms

1. Find grams of each element (remember to mult. that element by the number of times it occurs in the compound) 2. Find the total grams of the compound 3. Find the desired percent by dividing the desired element ( in this case carbon ) by the total to get the %.**
 * Percent Composition

24) Household sugar, sucrose, has the molecular formula C12H22O11. What is the % of carbon in sucrose, by mass? A. 26.7 % B. 33.3 % C. 41.4 % D. 42.1 % __E. 52.8 %__

1. Turn %'s into grams (29.17%--> 29.17g). 2. Divide each of the grams by the corisponding grams on the PT. 3. Divide each element by the smallest amount in step 2. 4. Match each # with its element. 5. Write out the compound.**
 * Emperical Formula

25) Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula. A. HNO __B. H2NO2__ C. HN6O16 D. HN16O7 E. H2NO3


 * Find the grams for the amounts you know: Carbon and Hydrogen. Set up the equation 12.01115(x) + 2.016(X) +2. Try the different amounts for x from the different answers.**

26) Alkanes are compounds of carbon and hydrogen with the general formula CnH2n+2. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane? A. 4 __B. 9__ C. 10 D. 13 E. 14