Chemistry 115 Exam One Study Guide

Silicon (Si) has three naturally occurring isotopes: 28Si, 29Si, and 30Si. Determine the number of protons, neutrons, and electrons in each.

(14p, 14e, and 14n) (14p, 14e, and 15n) (14p, 14e, and 16n)

Density of mercury, the only metal to exist as a liquid at room temperature, is 13.6g/cm^3. What is that density in pounds per cubic inch? 2.54 cm = 1 inch 2.205 lb. = 1 Kg

0.491 lb/in^3

Lithiumm a soft, gray solid with the lowest density of any metal, is a key component of advanced batteries. A slab of lithium weighs 1.49 X 10^3 mg and has sides that are 20.9 mm, 11.1 mm, and by 11.9 mm. Find the Density of lithium in g/cm^3. 10 mm = 1 cm.

0.539 g/cm^3

During the roasting of copper (1) sulfide, how many kilograms of oxygen are required to form 2.86 kg of copper (I) oxide?

0.959 kg O2

Gallium (Ga) is a key element in solar panels, calculators and other light-sensitive electronic devices. How many Ga atoms are in 2.85 X 10^-3 mol of gallium? Avagrado's number 6.022 X 10^23 atoms/mol

1.72 X 10^21 Ga atoms

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? Assume water has a density of 1.00 g/cm^3 at the temperature measurement.

1.84 g/cm^3

A child has a body temperature of 38.7 C and normal body temperature is 98.6 F. Does this child have a fever? What is the child's temperature in Kelvins?

101.7 C 374.85 K

Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of Magnesium Fluoride?

107 g

Silver (Ag, Z = 47) has two naturally occurring isotopes, 107Ag, and 109Ag. From the mass spectrometric data provided, calculate the atomic mass of Ag. Mass = 106.90509 Abundance = 51.84% Mass = 108.90476 Abundance = 48.16

107.87 amu

The area of a 15 in. pizza is 176.7 in^2. Express this area in cm^2.

1140. cm^2

How many grams of nitrogen gas form when 100. g of NH2 and 200. g of N2O4 are mixed? 2N2H4 + N2O4 = 3N2 +4H2O

131 g of N2

Copper is obtained from copper (I) sulfide by roasting it in the presence of oxygen gas to form powdered copper (I) oxide and gaseous sulfur dioxide. How many moles of oxygen are required to roast 10.0 mol of copper sulfide?

15.0 Moles of O2

Calculate the Molar Mass of Ca(BO2)2 X 6H2O

233.79 g/mol

How many mL of concentrated Nitric Acid (HNO3, 16.0 M) should be diluted with water in order to make 2.00 L of 2.00 M solution?

250 mL

Silicon makes p about 25% of the Earth's crust by mass, it is used widely in the modern electronics industry. It has three naturally occurring isotopes, 28Si, 29Si, and 30Si. Calculate the atomic mass of silicon. Mass = 27.976927 Abundance = 92.23 Mass = 28.976495 Abundance = 4.67 Mass = 29.973770 = Abundance = 3.10

28.0855 amu

Many international computer communications are carried out by optical fibers in cables laid along the ocean floor. If one strand of optical fiber weighs 1.19X10^-3 lbs/m, what is the mass (in kg) of a cable made of six strands of optical fiber each long enough to link New York and Paris (8.94 X 10^3km)? 2.205 lb. = 1 Kg 1 Km = 10^3m 6 fibers = 1 strand

28.9 X10^3 Kg

A 0.10 M HCl solution is used to stimulate the acid concentration of the stomach. How many liters of stomach acid react with a tablet of 0.10 g of magnesium hydroxide? Mg (OH)2 +2HCl = MgCl2 +2H2O

3.4 X 10^-2 L of HCl

Silver Ag, is used in jewelry and tableware but no longer in US coins. How many grams of Ag are in 0.0342 mol of Ag?

3.69 g

Compound 1 has a composition of 46.7 mass % of element A and 53.3 mass % of element B. A and B form a second binary compound (Compound 2). If the compositions of the two compounds are consistent with the law of multiple proportions, which of the following compositions could be that of compound 2? (23.4, 76.6) (30.4, 69.6) (33.3, 66.7) (53.3, 46.7) (73.3, 26.7)

30.4 mass % and 69.6 mass %

A graduated cylinder contains 19.9mL of water. When a small piece of galena, an ore lead, is added, it sinks and the volume increase to 24.5mL. What is the volume of the piece of galena in cm^3 and in L? 1mL = 1 cm^3

4.6cm^3 0.0046L

Household Sugar, sucrose, has the molecular formula C12H22O11. What is the % of carbon in sucrose, by mass?

42.1%

How many grams of oxygen are needed to react completely with 200.0g of ammonia NH3?

469.7

Kaolinite, a clay mineral with the formula Al4Si4O10(OH)8, is used as a filter 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.

55.81 Mass %

What is the percent yield for the reaction PCl3 +Cl2 = PCl5 If 119.3 g of PCl5 are formed when 61.3 g of Cl2 react with excess PCl3

66.3%

Naming Acids

If it's one ion it's hydro-name-ic acid If it's multiple ate = ic and ite = ous

Write empirical formulas for each of the compounds: Magnesium Nitride, Cadmium Iodide, Strontium Fluoride, Cesium Sulfide.

Mg3N2 CdI2 SrF2 Cs2S

Molarity

Moles/Liters

Analysis of a sample of an ionic compound yields 2.82 g of Na, 4.35 g of Cl nad 7.83 g of O. What is the empirical formula and the name of the compound?

NaClO4 this compound is Sodium Perchlorate

Naming Ionic Compounds

Names the cation (Metal) and then Anion (non-metal) The anion is named by adding the suffix "-ide"

What is the name of PCl3

Phosphorus trichloride

A sample of an unknown compound contains 0.21 mol of zinc, 0.14 mol of phosphorus, and 0.56 mol of oxygen. What is its empirical formula?

Zn3P2O8

What is the name of HCN gas dissolved in water?

Hydrocyanic acid

To wire your stereo equipment, you need 325 cm of peaker wire that sells for $0.15/ft. What is the price for the wire? 2.54cm per inch

$1.60

Silicon carbide (SiC)is made by reacting sand (silicon dioxide, SiO2 with powdered carbon at high temperature. Carbon Monoxide is also formed. What is the percent yield if 51.4 kg of SiC is recovered from processing 100.0 kg of sand? SiO2 + 3C = SiC +2CO2

77.0%

Analysis of 84.2 Kg of the uranium containing compound pitchblend shows it is composed of 71.4 Kg of uranium, with oxygen as the only other element. How many grams of uranium can be obtained from 102 Kg of pitchblend.

8.65 X 10^3 g

Predict the monoatomic ion formed by each of the following elements: A) Iodine (z = 53) B) Calcium (Z =20) C) Aluminum (Z = 13)

A) -1 charge B) +2 charge C) +3 charge

Ammonium Carbonate, a white solid that decomposes on warming, is a component of baking powder. A) How many formula units are in 41.6 g of Ammonium carbonate? B) How many O atoms are in this sample?

A) 2.61 X 10^23 (NH4)2CO3 Atoms b) 7.83 X 10^23 O atoms (3 O atoms)

Give the systematic name for each formula or the formula for each name for the following compounds: A) Fe(ClO4)2 B) Sodium Sulfite C)Ba(OH)2 X 8H2O

A) Iron (II) Perchlorate B) Na2SO3 C) Barium Hydroxide octahydrate

Consider the balanced equation for the combustion of propane, C3H8 C3H8 + 5O2 = 3CO2 + 4H2O A) What is the limiting reactant in a mixture containing 5.00 g of C3H8 and 10.0 g of O2? B) What mass of CO2 is formed when 1.00 g of C3H8 reacts completely?

A) O2 B) 3.036 g of CO2

Give the systematic name or each formula or the formula for each name for the following compounds: A) Tin(II)Fluoride B) CrI3 C)Ferric oxide D) CoS

A) SnF2 B) Chromium(III) Iodide C) Fe2O3 D) Cobalt (II) Sulfide

Numerical prefixes for these numbers 1, 2, 3, 4, 5, 6,7, 8, 9, 10,

Answer Mono, bi, tri, tetra, penta, hexa, hepta, octa, nona, deca

Name these 1. NH4+ 2. CH3COO- 3. Cn- 4. OH- 5. CIO- 6. CIO2- 7. CIO3- 8. NO2- 9. NO3- 10. MnO4- 11. H3O+ 12. CO3 (-2 charge) 13. HCO3 14. CrO4 (-2 charge) 15. CrO7 (-2 charge_ 16. O2 (-2 charge_ 17. PO4 (-3 charge) 18. HPO4 (-2 charge) 19. SO3 (-2 charge) 20. SO4 (-2 charge) 21. ClO4 22. ClO3 23. ClO2 24. ClO

Answers 1. Ammonium 2. Acetate 3. Cyanide 4. Hydroxide 5. HypoChlorite 6. Chlorite 7. Chlorate 8. Nitrite 9. Nitrate 10. Permaganate 11. Hydronium 12. Carbonate 13. Bicarbonate 14. Chromate 15. Dichromate 16. Peroxide 17. Phosphate 18. Hydrogen Phosphate 19. Sulfite 20.Sulfate 21. Perchlorate 22. Chlorate 23. Chlorite 24. Hypochlorite

Isotopes

Atoms with the Same number of protons different numbers of neutrons

What is Methane, Ethane, propane, and butane

CH4, C2H6, C3H8, C4H10

Elemental analysis of lactic acid (Molarity = 90.08 g/mol) shows it contains 40.0 mass % C, 6.71 % mass of H, and 53.3 % mass of O. Determine the empirical formula and the molecular formula for lactic acid. (Assuming there are 100 g of lactic acid)

Empirical Formula CH2O Molecular Formula C3H6O3

Physical or chemical change Frost forms on window Seed grows into a plant A match ignites into a flame Perspiration evaporates A silver fork tarnishes in air

Frost: Physical Seed: Chemical Match: Chemical Perspiration: Physical Fork: Chemical

Hydroxylamine nitrate contains 29.17 mass %N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula

H2NO2