Q&A Hero

Q: Metals react with oxygen gas to produce oxides with the general formula MxOy. Write a balanced chemical equation for the reaction of titanium with oxygen to yield titanium(IV) oxide. A.4 Ti(s) + O2(g) 2 Ti2O(s) B.Ti(s) + O2(g) TiO2(s) C.2 Ti(s) + O2(g) 2 TiO(s) D.Ti(s) + O(g) TiO(s) E.8 Ti(s) + O2(g) 2 Ti4O(s)

Q: The reaction of elemental chlorine with potassium iodide yields elemental iodine and potassium chloride. Write a balanced chemical equation for this reaction. A.Cl2(g) + KI(s) I(s) + KCl2(s) B.Cl2(g) + 2 KI(s) I2(s) + 2 KCl(s) C.Cl2(g) + KI2(s) I2(s) + KCl2(s) D.Cl(g) + KI(s) I(s) + KCl(s) E.Cl2(g) + 2 K2I(s) I2(s) + 2 K2Cl(s)

Q: When propane undergoes complete combustion, the products are carbon dioxide and water. __ C3H8(g) + __ O2(g) __ CO2(g) + __ H2O(g) What are the respective coefficients when the equation is balanced with the smallest whole numbers? A.1, 1, 1, 1 B.1, 3, 1, 3 C.1, 3, 3, 1 D.1, 5, 3, 4 E.2, 5, 3, 4

Q: The reaction of tetraphosphorus decaoxide with water produces phosphoric acid. __ P4O10 + __ H2O __ H3PO4 What are the respective coefficients when the equation is balanced with the smallest integer values? A.1, 1, 1 B.1, 3, 1 C.2, 4, 1 D.2, 6, 2 E.1, 6, 4

Q: Nitroglycerin decomposes violently according to the balanced chemical equation below. 2 C3H5(NO3)3() 3 N2(g) + 1/2 O2(g) + 6 CO2(g) + 5 H2O(g) Which of the following statements concerning this reaction is/are CORRECT? 1/ Two moles of nitroglycerine will produce three moles of nitrogen and five moles of water. 2/ Four molecules of nitroglycerine will produced one molecule of oxygen and twelve molecules of carbon dioxide. 3/ Six grams of nitroglycerine will produce nine grams of nitrogen and fifteen grams of water. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: The numerical quantity of a mole, 6.022 1023, is defined as the number of atoms in a specific mass of an element. What is the mass and the identity of the element used to define one mole?

Q: In which ionic compound, NaBr or KBr, is the force of attraction between anions and cations stronger?

Q: In reactions, metals generally lose electrons to become ________, and nonmetals gain electrons to become anions.

Q: What are the names of four metalloids?

Q: Oxygen and ________ are the two most abundant elements in the Earth's crust.

Q: Pure oxygen can exist as O2 or O3. Elements that exist in more than one distinct form are called ________.

Q: Buckminsterfullerene is a molecule composed of sixty ________ atoms.

Q: A 2.000 g sample of MgCl2xH2O is dried in an oven. When the anhydrous salt is removed from the oven, its mass is 0.9366 g. What is the value of x? A.1 B.3 C.6 D.8 E.12

Q: A 3.592 g sample of hydrated magnesium bromide, MgBr2xH2O, is dried in an oven. When the anhydrous salt is removed from the oven, its mass is 2.263 g. What is the value of x? A.1 B.3 C.6 D.8 E.12

Q: An ionic compound has the formula MCl2. The mass of 0.3011 mol of the compound is 62.69 grams. What is the identity of the metal? A.Ni B.Cu C.Sn D.Hg E.Ba

Q: A molecule is found to contain 47.35% by mass C, 10.60% by mass H, and 42.05% by mass O. What is the empirical formula for this molecule? A.C2H6O B.C3H4O C.C3H8O2 D.C4H6O2 E.C4H8O3

Q: Nitrogen and oxygen form an extensive series of oxides with the general formula NxOy. What is the empirical formula for an oxide that contains 30.44% by mass nitrogen? A.N2O B.NO C.NO2 D.N2O3 E.N2O5

Q: What is the mass percent of each element in sulfuric acid, H2SO4? A.2.055% H, 32.69% S, 65.25% O B.1.028% H, 32.69% S, 66.28% O C.28.57% H, 14.29% S, 57.17% O D.1.028% H, 33.72% S, 65.25% O E.2.016% H, 32.07% S, 65.91% O

Q: What is the mass percent of chlorine in magnesium chloride? A.25.53% B.37.24% C.40.67% D.59.33% E.74.47%

Q: If 1.00 g of an unknown molecular compound contains 8.35 1021 molecules, what is its molar mass? A.44.0 g/mol B.66.4 g/mol C.72.1 g/mol D.98.1 g/mol E.132 g/mol

Q: How many bromide ions are in 0.55 g of iron(III) bromide? A.1.1 1021 ions B.3.4 1021 ions C.3.3 1023 ions D.9.9 1023 ions E.2.9 1026 ions

Q: How many hydrogen atoms are present in 1.0 g of NH3? A.0.059 atoms B.0.18 atoms C.3.5 1022 atoms D.1.1 1023 atoms E.1.2 1022 atoms

Q: What is the mass of 0.50 mol chromium(III) sulfide? A.2.5 10"3 g B.5.9 10"3 g C.42 g D.1.0 102 g E.110 g

Q: What is the mass of 8.04 10"3 mol O2? A.2.51 10"4 g B.5.03 10"4 g C.0.129 g D.3.89 g E.0.257 g

Q: Calculate the number of moles of aluminum oxide in 6.83 g Al2O3.A.6.70 x 10"2 molB.6.96 x 102 molC.0.253 molD.0.127 molE.1.56 x 10"3 mol

Q: What is the molar mass of sodium sulfate? A.55.06 g/mol B.119.1 g/mol C.78.05 g/mol D.142.0 g/mol E.110.0 g/mol

Q: What is the molar mass of calcium chloride hexahydrate? A.75.53 g/mol B.111.0 g/mol C.117.0 g/mol D.183.6 g/mol E.219.1 g/mol

Q: A nail is coated with a 0.053 cm thick layer of zinc. The surface area of the nail is 8.59 cm2. The density of zinc is 7.13 g/cm3. How many zinc atoms are used in the coating?A.5.9 x 1020 atomsB.3.0 x 1022 atomsC.3.8 x 1022 atomsD.2.0 x 1024 atomsE.1.3 x 1026 atoms

Q: What mass of Al contains the same number of atoms as 3.0 g Pb? A.23 g B.0.014 g C.3.0 g D.0.39 g E.0.11 g

Q: The molar mass of platinum is 195.08 g/mol. What is the mass of 1.00 102 Pt atoms?A.8.51 x 10"25 gB.3.24 x 10"24 gC.1.67 x 10"22 gD.3.24 x 10"22 gE.3.24 x 10"20 g

Q: A 0.0050 g sample of boron contains ____ B atoms. A.4.6 10"4 B.7.7 10"28 C.2.8 1020 D.3.1 1021 E.3.3 1022

Q: What is the mass of 0.71 mol Na? A.1.2 10"24 g B.12 g C.16 g D.0.031 g E.32 g

Q: Calculate the number of moles in 0.48 g Cu. A.0.033 mol B.0.48 mol C.31 mol D.7.6 10-3 mol E.1.3 102 mol

Q: You have 2.50 g of each of the following elements: Ca, Cu, Cs, C, and Cr. Which sample contains the largest number of atoms? A.Ca B.Cu C.Cs D.C E.Cr

Q: What is the common name for PH3? A.laughing gas B.hydrazine C.nitroglycerin D.ammonia E.phosphine

Q: What is the correct name for CCl4? A.carbon chlorine B.tetracarbon chloride C.carbon tetrachloride D.carbon(IV) chloride E.tetrachlorocarbide

Q: What is the correct name for N2O4? A.nitrogen oxide B.dinitrogen tetraoxide C.nitrogen(II) oxide D.nitrogen tetraoxide E.dinitrogen tetraoxygen

Q: Predict which ionic compound has the highest melting point. A.KBr B.MgO C.RbI D.CaBr2 E.CsCl

Q: Which of the following statements concerning ionic compounds is/are correct?1.As ion charges increase, the attraction between oppositely charged ions increases.2.Although not electrically conductive like metals, ionic compounds are malleable.3.Positive and negative ions are attracted to each other by electrostatic forces.A.1 onlyB.2 onlyC.3 onlyD.1 and 3E.1, 2, and 3

Q: What is the correct name for Ca(CH3CO2)2? A.calcium(II) carbonate B.calcium carbonate C.calcium acetate D.acetic calcide E.calcium carbonide

Q: What is the correct name for MnS? A.manganese sulfide B.dimanganese sulfate C.dimanganese sulfide D.manganese(II) sulfate E.manganese(II) sulfide

Q: What is the correct name for SrCl2? A.strontium dichloride B.strontium dichlorine C.strontium(II) dichloride D.strontium chloride E.iodine strontide

Q: What is the correct name for NH4NO3? A.ammonia hydrogen nitrate B.ammonia hydrogen nitride C.ammonium nitric acid D.ammonium nitrate E.ammonium nitride

Q: What is the correct formula for iron(II) nitrate? A.Fe2(NO3)2 B.Fe2NO3 C.Fe(NO3)2 D.Fe3N2 E.FeNO3

Q: What is the correct formula for cobalt(III) bromide? A.CoBr B.CoBr3 C.Co2Br3 D.Co3Br2 E.Co3Br

Q: What is the correct formula for ammonium bromide? A.NH4Br B.(NH4)2Br C.NH3Br D.NH4Br2 E.NH2Br

Q: What is the correct formula for potassium dihydrogen phosphate? A.KH2PO4 B.K2HPO4 C.K2H2PO4 D.K3H2PO4 E.KH2P

Q: What is the correct formula for calcium nitrate? A.CaN B.Ca3N2 C.CaNO2 D.Ca3(NO3)2 E.Ca(NO3)2

Q: What is the charge on the copper ion in Cu3P?A.3-B.1-C.0D.1+E.3+

Q: Sodium sulfate has the chemical formula Na2SO4. Based on this information, the formula for chromium(III) sulfate is ____. A.CrSO4 B.Cr(SO4)3 C.Cr2(SO4)3 D.Cr2SO4 E.Cr3(SO4)2

Q: What is the correct formula for an ionic compound that contains barium ions and carbonate ions? A.BaCO3 B.Ba(HCO3)2 C.Ba2CO3 D.Ba2C E.Ba(CO3)2

Q: Which of the following formulas is not correct? A.AlPO4 B.KClO4 C.CaS D.Na(NO3)2 E.Na2HPO4

Q: What is the correct formula for an ionic compound that contains magnesium ions and phosphide ions? A.MgP B.MgP2 C.Mg3P2 D.Mg3(PO4)2 E.Mg2P3

Q: For a nonmetal in Group 6A of the periodic table, the most common monatomic ion will have a charge of ____.A.3-B.2-C.1-D.1+E.2+

Q: What charge is likely on a monatomic silver cation?A.2-B.1-C.1+D.2+E.3+

Q: Identify the ions in CaHPO4. A.Ca2+ and PO43" B.Ca2+ and HPO42" C.Ca+ and HPO4" D.Ca3+ and HPO43" E.Ca2+, H+, P3", and O2"

Q: Identify the ions present in Na2SO4. A.Na+, S2-, and O2- B.Na+, S2+, and O2- C.Na+ and SO42- D.Na+, S2-, and O2+ E.Na+ and SO4-

Q: Which atom is most likely to form a 2+ ion? A.scandium B.calcium C.aluminum D.oxygen E.fluorine

Q: Which element is most likely to form a 2" ion? A.K B.Mg C.P D.Br E.S

Q: C2H2F4 is the formula for two possible molecules. C2H2F4 is an example of a(n) A.structural formula. B.empirical formula. C.condensed formula. D.space-filling model. E.molecular formula.

Q: The formula of acetic acid, CH3CO2H, is an example of a(n) A.condensed formula. B.empirical formula. C.structural formula. D.ionic compound formula. E.mass spectrum.

Q: Which of the following elements is not a metalloid? A.boron B.selenium C.germanium D.arsenic E.silicon

Q: In which group of the following groups of the periodic table are all the elements nonmetals? A.2A B.3A C.5A D.6A E.7A

Q: Which three elements are likely to have similar chemical and physical properties? A.boron, silicon, and germanium B.sodium, magnesium, and aluminum C.sodium, potassium, and rubidium D.oxygen, sulfur, and chlorine E.carbon, nitrogen, and oxygen

Q: What halogen is in the third period? A.S B.Cl2 C.I2 D.H2 E.Ar

Q: What element is in the fourth period in Group 3A? A.Sb B.Ga C.In D.Si E.Tl

Q: Which of the following statements is/are CORRECT?1.The group 3A elements are also known as the chalcogens.2.The noble gases are sometimes called the rare gases because of their low abundances.3.The halogens, or group 7A elements, all exist as diatomic molecules.A.1 onlyB.2 onlyC.3 onlyD.2 and 3E.1, 2, and 3

Q: Group 1A elements are also known as A.alkaline earth metals. B.alkali metals. C.chalcogens. D.halogens. E.noble gases.

Q: Silver has two stable isotopes with masses of 106.90509 u and 108.9047 u. The average molar mass of silver is 107.868 u. What is the percent abundance of each isotope? A.50.0% Ag-107 and 50.0% Ag-109 B.51.8% Ag-107 and 48.2% Ag-109 C.55.4% Ag-107 and 44.6% Ag-109 D.48.2% Ag-107 and 51.8% Ag-109 E.44.6% Ag-107 and 55.4% Ag-109

Q: Copper has an average atomic mass of 63.55 u. If 69.17% of Cu exists as Cu-63 (62.93960 u), what is the identity and the atomic mass of the other isotope? A.Cu-64; 63.82 u B.Cu-64; 64.16 u C.Cu-65; 64.16 u D.Cu-65; 64.92 u E.Cu-66; 65.91 u

Q: An element consists of three isotopes. The abundance of one isotope is 92.21% and its atomic mass is 27.97693 u. The abundance of the second isotope is 4.70% and its atomic mass is 28.97649 u. The atomic mass of the third isotope is 29.97376 u. What is the average atomic mass of the element? A.28.09 u B.28.98 u C.28.96 u D.29.87 u E.29.07 u

Q: Rubidium has two naturally occurring isotopes. The average mass of Rb is 85.4678 u. If 72.15% of Rb is found as Rb-85 (84.9117 u), what is the mass of the other isotope? A.0.56 u B.85.68 u C.86.91 u D.86.02 u E.83.47 u

Q: The masses of isotopes and their abundances are determined experimentally using A.a mass spectrometer. B.an analytical balance. C.a centrifuge. D.filtration followed by distillation. E.electrolysis.

Q: Which of the following are a pair of isotopes? A. and B. and C. and D. and E. and

Q: Two isotopes of a given element will have the same number of ____, but a different number of ____ in their nucleus. A.protons, electrons B.electrons, protons C.protons, neutrons D.neutrons, protons E.electrons, neutrons

Q: Which two of the atoms below have the same number of neutrons? A. and B. and C. and D. and E. and

Q: Which of the following atoms contains the largest number of neutrons? A. B. C. D. E.

Q: How many neutrons are in an atom of gallium-71? A.71 B.40 C.111 D.31 E.102

Q: What is the atomic symbol for an element that has 30 neutrons and a mass number of 55? A.At B.Zn C.Co D.Mn E.Cs

Q: What is the identity of? A.Ni B.Zn C.Rn D.Ce E.Pd