SCIN131-Introduction to Chemistry-APUS-Midterm Review Assignment

Part 1 of 8 - 4.0/ 4.0 Points Question 1 of 22 2.0/ 2.0 Points According to the scientific method, what frequently leads to the development of a hypothesis?  A.observation  B.reason  C.none of the above  D.experiments  E.scientific law Answer Key: A Feedback: Good. This is the scientific method. Question 2 of 22 2.0/ 2.0 Points Who was quoted as saying "The most important idea in all of human knowledge is that all things are made of atoms"?  A.Richard Feynman  B.Antoine Lavoisier  C.Michael Faraday  D.John Dalton Answer Key: A
Part 2 of 8 - 6.0/ 6.0 Points Question 3 of 22 2.0/ 2.0 Points For the number 10405.630, which of the zeroes are considered significant?  A.Only the zero after the 1  B.Only the zero after the 4  C.Only the zero after the 3  D.Only the zeros after the 1 and 4.  E.All of the zeros are significant Answer Key: E Question 4 of 22 2.0/ 2.0 Points How many significant figures will be in the final answer of this calculation? 2.15 × 11.2 ÷ 0.8765 = ________  A.3  B.4  C.6  D.11  E.none of the above Answer Key: A Feedback: Good! Be sure to get these sig figs down at the beginning. Doing so will make it much easier for you later in the course. Question 5 of 22 2.0/ 2.0 Points My daughter loves yogurt covered raisins.  If I can buy a pound of yogurt covered raisins for $4.99, how much would it cost for me to purchase 1.25 kg of yogurt covered raisins?    A.$2.84  B.$6.24  C. $9.98  D.$13.72  E.$10.98 Answer Key: D Feedback: Good. This is a basic conversion problem.
Part 3 of 8 - 6.0/ 6.0 Points Question 6 of 22 2.0/ 2.0 Points How many calories are in 32 Calories?  A.3200  B.32  C.32000  D.320 Answer Key: C Question 7 of 22 2.0/ 2.0 Points `Which of the following is a homogeneous mixture?  A.liquid iron  B.chicken noodle soup  C.trail mix  D.brass  E.water Answer Key: D Question 8 of 22 2.0/ 2.0 Points `If I apply 0.108 kJ of energy in order to increase the temperature of a bar of gold from 30.0°C to 34.7°C, and the specific heat capacity of gold is 0.128 J/gC, what is the mass the bar of gold in grams?  A.1.28 × 10^2 g  B.1.08 × 10^2 g  C.1.8 × 10^2 g  D.6.5 × 10^1 g  E.none of the above Answer Key: C
Part 4 of 8 - 6.0/ 6.0 Points Question 9 of 22 2.0/ 2.0 Points `Which of the following concerning atoms is FALSE?  A.they comprise all matter  B.they are mostly empty space  C.they were not believed to exist until the 1800's  D.none of these are false  E.All of the above statements are false. Answer Key: C Feedback: See section 4.2 Question 10 of 22 2.0/ 2.0 Points `If aluminum were to form an ion, what would its charge be?  A.2-  B.1-  C.1+  D.2+  E.3+  F.3-  G.It is a transition metal, so it cannot be determined without further information. Answer Key: E Feedback: See the periodic table and section 4.7 Question 11 of 22 2.0/ 2.0 Points `Elements that are located to the right of the stair steps (zig-zag) line on the periodic table, but that do not touch it, would be classified as  A.metals  B.nonmetals  C.metalloids  D.noble gases  E.none of the above Answer Key: B
Part 5 of 8 - 6.0/ 6.0 Points Question 12 of 22 2.0/ 2.0 Points `What would be the proper way to write the name for a compound with the formula NaNO3?  A.sodium nitrogen trioxide  B.sodium nitrite  C.nitrate sodium  D.sodium nitrate  E.none of the above Answer Key: D Feedback: use naming rules and charge balancing Question 13 of 22 2.0/ 2.0 Points `If given the formula N2O7, how would you properly name it?  A. nitrogen heptoxide  B.dinitrogen heptoxide  C.dinitrogen oxide  D.dinitrogen hexaoxide  E.none of the above Answer Key: B Feedback: use naming rules Question 14 of 22 2.0/ 2.0 Points What is the correct name for a compound made of Calcium and Nitrogen?  A.calcium nitride  B.calcium dinitride  C.calcium (II) nitride  D.calcium trinitride  E.none of the above Answer Key: A Feedback: use naming rules
Part 6 of 8 - 6.0/ 6.0 Points Question 15 of 22 2.0/ 2.0 Points `Let's be honest, caffeine (C8H10N4O2) makes the world go 'round. What is the mass in grams of 2.00 moles of this wonderdrug?  A.194  B.97  C.388  D.24  E.48 Answer Key: C Question 16 of 22 2.0/ 2.0 Points `Your physician has told you to increase your potassium intake by eating more bananas. The problem is, he wrote this down in terms of moles and not bananas. He said to eat at least 0.0216 moles of potassium per day. An average banana contains about 422 mg of potassium. How many bananas do you need to eat each day?  A.1  B.2  C.3  D.4  E.5 Answer Key: B Feedback: Good. See section 6.3 Question 17 of 22 2.0/ 2.0 Points Salicyclic acid (C7H6O3) is commonly the active ingredient in face washes designed to help with acne.  What is the mass percent of carbon in this compound?  A.60.9%  B.6.09%  C.34.7%  D.3.47% Answer Key: A Feedback: Good. See section 6.6-6.7
Part 7 of 8 - 6.0/ 6.0 Points Question 18 of 22 2.0/ 2.0 Points `Suppose you pour a beaker of ammonium nitrate solution into a beaker containing a solution of sodium chloride. What type of reaction would you expect to occur?  A.oxidation-reduction  B.gas evolution  C.precipitation  D.acid-base neutralization  E.no reaction Answer Key: E Feedback: Good. See sections 7.5-7.6 Question 19 of 22 2.0/ 2.0 Points How is the best way to describe an aqueous solution?  A.water that contains a dissolved compound  B.any liquid that contains a dissolved compound  C.an ionic compound containing water dissolved in it.  D.all of these are accurate Answer Key: A Feedback: Good. see section 7.5 Question 20 of 22 2.0/ 2.0 Points Which of the following compounds is soluble?  A.strontium carbonate  B.copper carbonate  C.sodium carbonate  D.calcium carbonate Answer Key: C Feedback: Good. See the solubility table
Part 8 of 8 - 4.0/ 4.0 Points Question 21 of 22 2.0/ 2.0 Points My grandmother left me some silver years ago.  I opened the box containing the silver and it had tarnished.  Using the equation below, if I had 300 g of silver that had tarnished and 175g H2S, which would be the limiting reactant? 2 Ag(s) + H2S(g) → Ag2S(s) + H2(g)  A.silver sulfide  B.silver  C.hydrogen  D.There is no limiting reactant in this case  E.hydrogen sulfide Answer Key: B Feedback: Good. see section 8.6 Question 22 of 22 2.0/ 2.0 Points Solid Iron (III) reacts with oxygen gas to form iron (III) oxide, which is the compound we see when rust is present.  Based on this information, which of the following is true? 4Fe + 3O2 ---> 2Fe2O3  A.4 moles of iron will need 2 moles of oxygen gas to fully react  B.12 moles of iron, if reacted completely, can produce 8 moles of iron (III) oxide.  C.9 moles of oxygen can produce 9 moles of Iron (III) oxide  D.6 moles of oxygen can react completely to produce 6 moles of iron (III) oxide.  E.none of the above Answer Key: E Feedback: Good. See section 8.6
Part 1 of 8 - 4.0/ 4.0 Points Question 1 of 22 2.0/ 2.0 Points Which of the following would be considered a theory?  A.Hot air rises.  B.Gasoline has a very strong odor.  C.Glass is fragile.  D.Helium balloons float because helium is less dense than air. Answer Key: D Feedback: Good. A theory is a predictive model of nature, but it must be based on quantifiable measurements. It must involve objective measurements, not subjective evaluations like smell or personal opinions. Question 2 of 22 2.0/ 2.0 Points A sample of wood with a mass of 3.0 grams was burned in an open dish. The ashes weighed 1.2 grams. What happened to the rest of the wood?  A.Nothing, the burned wood simply has a mass of 1.2 grams.  B.The remaining mass was destroyed.  C.The remaining 1.8 grams was converted into heat.  D.The remaining 1.8 grams was converted into gaseous compounds.  E.none of the above Answer Key: D Feedback: Good! It's the law of conservation here. It had to go somewhere, so if it's not there, it must be in gaseous form.
Part 2 of 8 - 2.0/ 6.0 Points Question 3 of 22 0.0/ 2.0 Points The correct decimal representation of 1.201 × 10-7 is:  A.12010000  B.0.0000001201  C.1201.000  D.0.0001201  E.none of the above Answer Key: B Feedback: Scientific notation is discussed in section 2.2 of the text. Question 4 of 22 2.0/ 2.0 Points The correct multiplier for the prefix pico is:  A.10-9  B.10-3  C.10-6  D.10-12  E.none of the above Answer Key: D Feedback: Good. Prefixes and their multipliers are discussed in section 2.5 of the text. Question 5 of 22 0.0/ 2.0 Points The correct multiplier for the prefix micro is:  A.10-6  B.106  C.10-9  D.103  E.none of the above Answer Key: A Feedback: Prefixes and their multipliers are discussed in section 2.5 of the text.
Part 3 of 8 - 6.0/ 6.0 Points Question 6 of 22 2.0/ 2.0 Points . Which of the following items is a mixture?  A.helium  B.sugar  C.water  D.brass  E.none of the above Answer Key: D Question 7 of 22 2.0/ 2.0 Points Which of the following is a heterogenous mixture?  A.milk  B.sugar water  C.air  D.raisin bran  E.none of the above Answer Key: D Question 8 of 22 2.0/ 2.0 Points Which of the following items is a physical property?  A.the combustion of gasoline  B.the tarnishing of a copper statue  C.the odor of spearmint gum  D.the corrosive action of acid rain on granite  E.none of the above Answer Key: C
Part 4 of 8 - 6.0/ 6.0 Points Question 9 of 22 2.0/ 2.0 Points The number of protons in the nucleus of an atom  A.identifies the atom as a particular element.  B.is called the atomic number.  C.is given the symbol "Z."  D.is the same for all isotopes of an element.  E.all of the above Answer Key: E Question 10 of 22 2.0/ 2.0 Points All of the following statements about different elements are true EXCEPT:  A.Sulfur is considered a metalloid.  B.Manganese is a transition metal.  C.Iodine is a halogen.  D.Krypton is one of the noble gases.  E.Barium is an alkaline earth metal. Answer Key: A Question 11 of 22 2.0/ 2.0 Points What is the charge on the ion formed by aluminum?  A.13+  B.3+  C.3-  D.5-  E.none of the above Answer Key: B
Part 5 of 8 - 6.0/ 6.0 Points Question 12 of 22 2.0/ 2.0 Points Ammonium fluoride is considered which of the following?  A.molecular element  B.ionic compound  C.atomic element  D.molecular compound  E.none of the above Answer Key: B Question 13 of 22 2.0/ 2.0 Points What is the correct formula for potassium dichromate?  A.K(CrO4)2  B.K2CrO4  C.KCr2O7  D.K2Cr2O7  E.none of the above Answer Key: D Question 14 of 22 2.0/ 2.0 Points A certain oxyacid is derived from the oxyanion SO32-. The formula for the oxyacid is  A.H2SO3.  B.H3SO3.  C.HSO3.  D.H2SO4.  E.none of the above Answer Key: A
Part 6 of 8 - 6.0/ 6.0 Points Question 15 of 22 2.0/ 2.0 Points How many moles of fluorine are in 3.2 moles of xenon hexafluoride?  A.19.2  B.12.8  C.22.4  D.16  E.none of the above Answer Key: A Question 16 of 22 2.0/ 2.0 Points What is the mass percent of chlorine in hydrochloric acid?  A.2.8  B.70.1  C.97.2  D.35.5  E.none of the above Answer Key: C Question 17 of 22 2.0/ 2.0 Points One mole of oxygen gas has a mass of ________ g.  A.16.0  B.6.022 × 1023  C.32.0  D.8  E.none of the above Answer Key: C
Part 7 of 8 - 6.0/ 6.0 Points Question 18 of 22 2.0/ 2.0 Points Which of the following equations is NOT balanced properly?  A.4NH3 + 14O2 → 4NO2 + 6H2O  B.2NaHCO3 → Na2CO3 + CO2 + H2O  C.2Cr + 6HCl → 2CrCl3 + 3H2  D.Cr2(SO4)3 + 6KOH → 2Cr(OH)3 + 3 K2SO4  E.none of the above Answer Key: A Question 19 of 22 2.0/ 2.0 Points Before a chemical equation can be written, one must know  A.the molar mass of all the compounds.  B.the number of moles of all reactants and products.  C.the atomic mass of all the elements involved.  D.the symbols and formulas of all reactants and products.  E.none of the above. Answer Key: D Question 20 of 22 2.0/ 2.0 Points What are the coefficients for the following reaction when it is properly balanced?___HCl + ___Mg → ___MgCl2 + ___ H2  A.2, 1, 2, 2  B.2, 1, 1, 1  C.1, 2, 1/2, 1  D.1, 1, 1, 2  E.none of the above Answer Key: B
Part 8 of 8 - 4.0/ 4.0 Points Question 21 of 22 2.0/ 2.0 Points The theoretical yield of a reaction is 75.0 grams of product and the actual yield is 42.0g. What is the percent yield?  A.75.0  B.178  C.56.0  D.31.5  E.none of the above Answer Key: C Question 22 of 22 2.0/ 2.0 Points If the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%. How many grams were actually produced?  A.32  B.5400  C.56  D.1.8  E.none of the above Answer Key: A
Part 1 of 8 -	4.0/ 4.0 Points

Question 1 of 22 2.0/ 2.0 Points Which of the following would be considered a theory?  A.Hot air rises.  B.Gasoline has a very strong odor.  C.Glass is fragile.  D.Helium balloons float because helium is less dense than air. Answer Key: D Feedback: Good. A theory is a predictive model of nature, but it must be based on quantifiable measurements. It must involve objective measurements, not subjective evaluations like smell or personal opinions.
Question 2 of 22 2.0/ 2.0 Points Who discovered the law of conservation of mass?  A.Nivaldo Tro  B.John Dalton and Antoine Lavoisier  C.Antoine Lavoisier  D.John Dalton  E.none of the above Answer Key: C Feedback: Good. It was Lavoisier.
Part 2 of 8 -	6.0/ 6.0 Points

Question 3 of 22 2.0/ 2.0 Points How many significant digits should be reported in the answer to the following calculation? (4.3 - 3.7) × 12.3=  A.2  B.3  C.1  D.4  E.none of the above Answer Key: C Feedback: Good. This was covered in section 2.4 of the text.
Question 4 of 22 2.0/ 2.0 Points How many liters are in 333 mL?  A.0.333  B.3.33  C.3.33 × 105  D.33.3  E.none of the above Answer Key: A Feedback: Good. This is a basic conversion problem.
Question 5 of 22 2.0/ 2.0 Points The correct scientific notation for the number 0.00050210 is:  A.5.021 × 10-4  B.5.0210 × 10-4  C.5.0210 × 104  D.5.021 × 104  E.none of the above Answer Key: B Feedback: Good. Scientific notation is discussed in section 2.2 of the text.
Part 3 of 8 -	6.0/ 6.0 Points

Question 6 of 22 2.0/ 2.0 Points What is the value of 335 K on the Celsius temperature scale?  A.167  B.608  C.66.4  D.62  E.none of the above Answer Key: D
Question 7 of 22 2.0/ 2.0 Points How would you classify salt water?  A.mixture-homogeneous  B.pure substance-compound  C.mixture-heterogeneous  D.pure substance-element  E.none of the above Answer Key: A
Question 8 of 22 2.0/ 2.0 Points A solution is an example of a (an)  A.element.  B.heterogeneous mixture.  C.compound.  D.homogeneous mixture.  E.pure substance. Answer Key: D
Part 4 of 8 -	6.0/ 6.0 Points

Question 9 of 22 2.0/ 2.0 Points Group 7A elements are also called:  A.halogens.  B.alkaline earth metals.  C.alkali metals.  D.noble gases.  E.none of the above Answer Key: A
Question 10 of 22 2.0/ 2.0 Points Mg is a member of which family?  A.alkaline earth metals  B.alkali metals  C.halogens  D.noble gases  E.none of the above Answer Key: A
Question 11 of 22 2.0/ 2.0 Points The nucleus of an atom consists mainly of  A.protons and electrons.  B.protons and neutrons.  C.neutrons and electrons.  D.protons, neutrons, and electrons.  E.none of the above Answer Key: B
Part 5 of 8 -	6.0/ 6.0 Points

Question 12 of 22 2.0/ 2.0 Points How many carbon atoms are in the formula Al2(CO3)3?  A.1  B.6  C.3  D.9  E.none of the above Answer Key: C
Question 13 of 22 2.0/ 2.0 Points The charge of a vanadium ion in the compound V2O5 is:  A.10-  B.2+  C.5+  D.10+  E.none of the above Answer Key: C
Question 14 of 22 2.0/ 2.0 Points Which metal atom below would NOT be involved in formation of a Type II compound?  A.Cr  B.Fe  C.Ba  D.Mn  E.none of the above Answer Key: C
Part 6 of 8 -	6.0/ 6.0 Points

Question 15 of 22 2.0/ 2.0 Points What is the molar mass of aluminum sulfate?  A.315.2 g/mol  B.342.2 g/mol  C.278.0 g/mol  D.306.2 g/mol  E.123.0 g/mol Answer Key: B
Question 16 of 22 2.0/ 2.0 Points Which of the following compounds has the highest mass percent of "O"?  A.Mn3O2  B.MnO  C.Mn2O3  D.MnO2  E.none of the above Answer Key: D
Question 17 of 22 2.0/ 2.0 Points How many hydrogen atoms are in 35.0 grams of hydrogen gas?  A.1.05 × 1025  B.4.25 × 1025  C.2.12 × 1025  D.2.09 × 1025  E.none of the above Answer Key: A
Part 7 of 8 -	6.0/ 6.0 Points

Question 18 of 22 2.0/ 2.0 Points When solid NaCl is stirred into water, which of the following is NOT true?  A.The NaCl will fail to dissociate.  B.The solution will taste salty.  C.The solution will conduct electricity.  D.Individual sodium and chloride ions are present.  E.none of the above Answer Key: A
Question 19 of 22 2.0/ 2.0 Points Which of the following everyday substances does NOT typically contain an acid?  A.lemons  B.vinegar  C.limes  D.soap  E.all of the above Answer Key: D
Question 20 of 22 2.0/ 2.0 Points An aqueous solution is:  A.water with another compound dissolved in it.  B.any liquid with another compound dissolved in it.  C.an ionic compound with water dissolved in it.  D.water with a molecular compound dissolved in it.  E.none of the above Answer Key: A
Part 8 of 8 -	4.0/ 4.0 Points

Question 21 of 22 2.0/ 2.0 Points How many grams of water are made from the reaction of 4.0 grams of hydrogen gas? Given the reaction: 2H2 + O2 → 2H2O  A.72  B.36  C.18  D.4.5  E.not enough information Answer Key: B

Question 22 of 22 2.0/ 2.0 Points Consider the following generic chemical equation: 2W + 3X → 3Y + Z When 5 units of W and 6 units of X are allowed to react, the limiting reactant would be:  A.Y  B.X  C.W  D.Z  E.There is no limiting reactant in this situation. Answer Key: B

Part 1 of 8 - 4.0/ 4.0 Points Question 1 of 22 2.0/ 2.0 Points Which of the following is an example of a scientific law?  A.When a can of soda pop is opened, a fizzing sound is heard.  B.Flammable objects contain phlogiston.  C.In a chemical reaction, matter is neither created nor destroyed.  D.All matter is composed of small, indestructible particles called atoms.  E.none of the above Answer Key: C Feedback: Good. This is Lavoisier's Law of Conservation of Mass. Question 2 of 22 2.0/ 2.0 Points Which of the following would be considered a theory?  A.Hot air rises.  B.Gasoline has a very strong odor.  C.Glass is fragile.  D.Helium balloons float because helium is less dense than air. Answer Key: D Feedback: Good. A theory is a predictive model of nature, but it must be based on quantifiable measurements. It must involve objective measurements, not subjective evaluations like smell or personal opinions.

Part 2 of 8 - 6.0/ 6.0 Points Question 3 of 22 2.0/ 2.0 Points How many milliliters are in 17.5 L?  A.175  B.1.75 × 10^4  C.1.75 × 10^3  D.1.75 × 10^-2  E.none of the above Answer Key: B Question 4 of 22 2.0/ 2.0 Points Suppose a thermometer has marks at every one degree increment and the mercury level on the thermometer is exactly between the 25 and 26 degree Celsius marks. We should properly report the temperature measurement as  A.25.50°C  B.25.55°C  C.26°C  D.25.5°C  E.25°C Answer Key: D Feedback: Good. Always go one number past the most certain digit. This is covered in section 2.3 of the book. Question 5 of 22 2.0/ 2.0 Points The correct number of significant figures in the number 9.080 x 10-4 is  A.4  B.3  C.5  D.ambiguous  E.none of the above Answer Key: A Feedback: Good. This is discussed in section 2.3 of the text.

Part 3 of 8 - 6.0/ 6.0 Points Question 6 of 22 2.0/ 2.0 Points A 15.0 gram lead ball at 25.0°C was heated with 40.5 joules of heat. Given the specific heat of lead is 0.128 J/g∙°C, what is the final temperature of the lead?  A.46.1°C  B.77.8°C  C.0.844°C  D.21.1°C  E.none of the above Answer Key: A Question 7 of 22 2.0/ 2.0 Points Which of the following is a heterogenous mixture?  A.milk  B.sugar water  C.air  D.raisin bran  E.none of the above Answer Key: D Question 8 of 22 2.0/ 2.0 Points How would you classify salt water?  A.mixture-homogeneous  B.pure substance-compound  C.mixture-heterogeneous  D.pure substance-element  E.none of the above Answer Key: A

Part 4 of 8 - 6.0/ 6.0 Points Question 9 of 22 2.0/ 2.0 Points How many electrons are in Br-?  A.36  B.7  C.4  D.34  E.none of the above Answer Key: A Question 10 of 22 2.0/ 2.0 Points Group 8A elements are also called:  A.alkaline earth metals.  B.noble gases.  C.alkali metals.  D.halogens.  E.none of the above Answer Key: B Question 11 of 22 2.0/ 2.0 Points What is the correct chemical symbol for mercury?  A.My  B.Hm  C.Hy  D.Me  E.none of the above Answer Key: E

Part 5 of 8 - 6.0/ 6.0 Points Question 12 of 22 2.0/ 2.0 Points What is the formula mass of copper(II) fluoride?  A.90.00  B.146.10  C.165.10  D.101.55  E.none of the above Answer Key: D Question 13 of 22 2.0/ 2.0 Points What is the proper name for HBr (aq)?  A.hydrobromous acid  B.hydrobromic acid  C.bromous acid  D.hydrousbromic acid  E.none of the above Answer Key: B Question 14 of 22 2.0/ 2.0 Points What is the name of the ionic compound made of beryllium and chlorine?  A.beryllium chloride  B.beryllium dichloride  C.beryllium(II) chloride  D.monoberyllium dichloride  E.none of the above Answer Key: A

Part 6 of 8 - 6.0/ 6.0 Points Question 15 of 22 2.0/ 2.0 Points One mole of ammonium nitrate contains:  A.2 moles of nitrogen.  B.1 mole of nitrogen.  C.2 moles of oxygen.  D.3 moles of hydrogen.  E.none of the above Answer Key: A Question 16 of 22 2.0/ 2.0 Points The empirical formula of a compound:  A.is the same as the molecular formula.  B.indicates the simplest ratio of atoms in the compound.  C.describes the mass relationships in a molecule.  D.indicates the structure of the molecule.  E.none of the above Answer Key: B Question 17 of 22 2.0/ 2.0 Points What would the empirical formula be for the molecular compound C6H9O4?  A.C2H3O2  B.C3H6O2  C.C3H9O4  D.CH3O2  E.none of the above Answer Key: E

Part 7 of 8 - 6.0/ 6.0 Points Question 18 of 22 2.0/ 2.0 Points All of the following compounds are soluble in water EXCEPT  A.PbCl2.  B.NH4Cl.  C.CaCl2.  D.FeCl3.  E.NaCl. Answer Key: A Question 19 of 22 2.0/ 2.0 Points When the equation __Ca3N2 + __H2O → __Ca(OH)2 + __NH3 is balanced, the coefficient of H2O is:  A.3  B.2  C.6  D.12  E.none of the above Answer Key: C Question 20 of 22 2.0/ 2.0 Points What are the coefficients for the following reaction when it is properly balanced?___O2 + ___CH4 → ___CO2 + ___H2O  A.2, 1, 1, 2  B.2, 3, 2, 2  C.2, 1, 3, 1  D.1, 3, 2, 1  E.none of the above Answer Key: A

Part 8 of 8 - 4.0/ 4.0 Points Question 21 of 22 2.0/ 2.0 Points Many metals react with halogens to give metal halides. For example, 2 Al (s) + 3 Cl2(g) → 2 AlCl3 (s) If you begin with 13.5 g of aluminum,  A.you will need 23.6 g Cl2 for complete reaction and will produce 66.7 g of AlCl3.  B.you will need 53.2 g Cl2 for complete reaction and will produce 66.7 g of AlCl3.  C.you will need 11.8 g Cl2 for complete reaction and will produce 49.0 g of AlCl3.  D.you will need 26.6 g Cl2 for complete reaction and will produce 49.0 g of AlCl3.  E.none of the above Answer Key: B Question 22 of 22 2.0/ 2.0 Points Consider the following generic chemical equation: 2A + 5B → C + 3D If you react 4 units of A with 10 units of B, which statement is TRUE?  A.Substance B will be the limiting reactant.  B.Substance C cannot be formed from this reaction.  C.There is just enough of A and B so that everything reacts completely.  D.Substance A will be the limiting reactant.  E.none of the above Answer Key: C

Question 1 of 22 2.0/ 2.0 Points The key to success in chemistry is:  A.commitment.  B.curiosity.  C.mathematical skills.  D.practice.  E.all of the above Answer Key: E Feedback: Good! All of these are needed to succeed. Question 2 of 22 2.0/ 2.0 Points Which of the following is an example of a scientific law?  A.When a can of soda pop is opened, a fizzing sound is heard.  B.Flammable objects contain phlogiston.  C.In a chemical reaction, matter is neither created nor destroyed.  D.All matter is composed of small, indestructible particles called atoms.  E.none of the above Answer Key: C Feedback: Good. This is Lavoisier's Law of Conservation of Mass.

Part 2 of 8 - 6.0/ 6.0 Points Question 3 of 22 2.0/ 2.0 Points There are exactly 2.54 centimeters in 1 inch. When using this conversion factor, how many significant figures are you limited to?  A.1  B.3  C.ambiguous  D.depends on if you are using it in multiplication/division or addition/subtraction  E.infinite number of significant figures Answer Key: E Feedback: Good. This is covered in section 2.3 in the text. Question 4 of 22 2.0/ 2.0 Points How many liters are in 333 mL?  A.0.333  B.3.33  C.3.33 × 105  D.33.3  E.none of the above Answer Key: A Feedback: Good. This is a basic conversion problem. Question 5 of 22 2.0/ 2.0 Points Given the density of Au is 19.3 g/cm3, determine the mass of gold in an ingot with the dimensions of 10.0 in × 4.00 in × 3.00 in.  A.3.80 × 104  B.2.32 × 103  C.0.161  D.102  E.none of the above Answer Key: A Feedback: Good. This is both a density and a conversion problem. You have to get your units the same.

Part 3 of 8 - 6.0/ 6.0 Points Question 6 of 22 2.0/ 2.0 Points Which of the following is a homogeneous mixture?  A.trail mix  B.water  C.stainless steel  D.molten iron  E.none of the above Answer Key: C Question 7 of 22 2.0/ 2.0 Points How would you classify raisin bran?  A.mixture-homogeneous  B.pure substance-element  C.mixture-heterogeneous  D.pure substance-compound  E.none of the above Answer Key: C Question 8 of 22 2.0/ 2.0 Points A 15.0 gram lead ball at 25.0°C was heated with 40.5 joules of heat. Given the specific heat of lead is 0.128 J/g∙°C, what is the final temperature of the lead?  A.46.1°C  B.77.8°C  C.0.844°C  D.21.1°C  E.none of the above Answer Key: A

Part 4 of 8 - 6.0/ 6.0 Points Question 9 of 22 2.0/ 2.0 Points Group 2A elements are also called:  A.noble gases.  B.alkaline earth metals.  C.alkali metals.  D.halogens.  E.none of the above Answer Key: B Question 10 of 22 2.0/ 2.0 Points Group 8A elements are also called:  A.alkaline earth metals.  B.noble gases.  C.alkali metals.  D.halogens.  E.none of the above Answer Key: B Question 11 of 22 2.0/ 2.0 Points How many protons and neutrons are in Cl-37?  A.17 protons, 37 neutrons  B.17 protons, 20 neutrons  C.37 protons, 17 neutrons  D.20 protons, 17 neutrons  E.none of the above Answer Key: B

Part 5 of 8 - 6.0/ 6.0 Points Question 12 of 22 2.0/ 2.0 Points Fluorine is considered which of the following?  A.molecular element  B.molecular compound  C.atomic element  D.ionic compound  E.none of the above Answer Key: A Question 13 of 22 2.0/ 2.0 Points Which of the following has the largest formula mass?  A.SiO2  B.NO2  C.CO2  D.SO2  E.H2O Answer Key: D Question 14 of 22 2.0/ 2.0 Points What would the formula of diiodine pentasulfide be?  A.I2S5  B.I5S2  C.I2S7  D.I4S9  E.none of the above Answer Key: A

Part 6 of 8 - 6.0/ 6.0 Points Question 15 of 22 2.0/ 2.0 Points What is the mass of 1.56 × 1021 atoms of magnesium in grams?  A.4.72 × 10-5  B.0.0630  C.1.07 × 10-4  D.0.142  E.none of the above Answer Key: B Question 16 of 22 2.0/ 2.0 Points The empirical formula of a compound:  A.is the same as the molecular formula.  B.indicates the simplest ratio of atoms in the compound.  C.describes the mass relationships in a molecule.  D.indicates the structure of the molecule.  E.none of the above Answer Key: B Question 17 of 22 2.0/ 2.0 Points If 2.01 × 1023 atoms of an element from Group IA of the periodic table has a mass of 7.675 grams, this element is most likely  A.Rb.  B.Na.  C.Li.  D.K.  E.Cs. Answer Key: B

Part 7 of 8 - 6.0/ 6.0 Points Question 18 of 22 2.0/ 2.0 Points What type of a reaction occurs when a hydrochloric acid solution is mixed with a sodium bicarbonate solution?  A.acid-base neutralization  B.precipitation  C.oxidation-reduction  D.gas evolution  E.no reaction Answer Key: D Question 19 of 22 2.0/ 2.0 Points Which of the following statements about balancing reactions is FALSE?  A.Subscripts are multiplied by the coefficients to determine the number of atoms in a compound.  B.When coefficients are added the type of compounds is changed in the chemical reaction.  C.If there is no coefficient or subscript, a one is implied.  D.Coefficients are added to compounds to ensure both sides of the reaction have equal numbers of each atom.  E.All of the above statements are true. Answer Key: B Question 20 of 22 2.0/ 2.0 Points Which of the following is NOT evidence that a chemical reaction has occurred?  A.gas formation when chemicals are contacted with each other  B.color change when chemicals are contacted with each other  C.solid formation when chemicals are contacted with each other  D.emission of light when chemicals are contact with each other  E.All of the above are evidence of a chemical reaction. Answer Key: E

Part 8 of 8 - 4.0/ 4.0 Points Question 21 of 22 2.0/ 2.0 Points Consider the following reaction: 2 Mg + O2 → 2 MgO △H rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg.  A.-601.5 kJ  B.-4812 kJ  C.-1203 kJ  D.-2406 kJ  E.none of the above Answer Key: D Question 22 of 22 2.0/ 2.0 Points A chemist wishes to perform the following reaction: N2 + 3 H2 → 2 NH3 If only 14.0 g of N2 is available, what is the minimum amount, in grams, of H2 needed to completely react with this quantity of N2?  A.3.03 g  B.1.01 g  C.1.51 g  D.6.06 g  E.none of the above Answer Key: A