Understanding Chemical Bonds and Molecular Structure in Chemistry
School
Greeley West High School**We aren't endorsed by this school
Course
CHEMISTRY 1
Subject
Chemistry
Date
Dec 12, 2024
Pages
10
Uploaded by pcherry
Name Period High School Chemistry Semester 1Unit 3Chapter 6, 3.1 and 3.2Fall 2019/2020
1.As a bond between two atoms becomes more polar, the differencein their electro-negativities is usually observed to be a. Greaterb. Smallerc. Constantd. Negative2.The central atom in CO2has only two electron groups, they will be founda.At 90˚ to one anotherb.On the same side of the central atomc.At 120°C to one anotherd.On opposite sides of the central atom3.In a molecule having three electron groups, if the central atom has three bonding pairsand NO lone pairsthe bond angle will be approximately a. 90˚b. 109˚c. 120°d. 180˚4.BCl3has a trigonal planer structure. This molecule would most likely be.a. Polar b. Nonpolar5.For most atoms, other than hydrogen, that form covalent bonds, a full outer level consists ofa.8 electronsb.2 electronsc.18 electronsd.32 electrons6.Which of the following bonds is the leastpolar given the following electro-negativities? C = 2.50, O = 3.5, Cl = 2.8, Si = 1.7, N = 3.1a.C – Ob.O – Clc. Si - Od.N – O
7.The particles held together by intermolecular forceswould bea. Atomsb. Moleculesc. Ionsd. Protons8.Which element is most likely to be stable with less than 8 valence electrons?a. Xenonb. Chlorinec. Sulfurd. Boron9. Which intermolecularforce is present in all moleculesa.London dispersion forcesb.Hydrogen bondingc. Ion-dipoled. Dipole-dipole10.Which of the following lists the intermolecular forcesin increasing order of strength?a.London dispersion force, Dipole-dipole, Hydrogen bondsb.Dipole-dipole, London dispersion force, Hydrogen bondsc.Hydrogen bonds, Dipole-dipole, London Dispersion forced.London dispersion force, Hydrogen bonds, Dipole-dipole11. Which compound would you expect to have a higher boiling point?a. CH3CH2OHb. CH3OHc. CH4d. CH3CH2CH2CH2OH12.The purpose of the “staircase”on the Periodic Table is to separatea.Solids from gases b.Gases from metalsc.Metals from liquidsd.Metals from nonmetals
13.Which group of solid elements are poor electrical conductors a room temperature, but become better conductors at high temperature; in other words are semiconductors?a. Metalsb. Nonmetalsc. Metalloidsd.Transition metals14.Which of the following sets of elements is MOST likely to have similar characteristics? a.Copper (Cu), silver (Ag) and gold (Au) b.Nickel (Ni), copper (Cu), and zinc (Zn) c.Nickel (Ni), silver (Ag), and mercury (Hg) d.Sodium (Na), magnesium (Mg) and aluminum (Al) 15. The correct order for DECREASING atomic radius (size)of the four atoms given in each ofthe choices below is a.I > F > Cl > Br b.F > N > O > C c.Cs > Rb > K > Lid.F > Cl > Br > I 16. As you go down a Group(or Family) which of the following trends DECREASES? a.Atomic radius b.Atomic Mass c.Electronegativityd.Atomic number 17. Which of the Groups (Families) listed below contains s- block elements? a.The Alkaline Earth Metals b.The Transition Metals c.The Halogens d.The Actinide Series 18. Elements in the same Periodic Group have the samea.Atomic Radius b.Nuclear charge c.Number of valence electronsd.Energy level of outer electrons <means less than>means greater than
Use the table below to answer questions 19-2219. In the figure above, what is the approximate atomic mass of element Y? a.5 b.10 c.15 d.25 20. Imagine that a new element, Q, is discovered. The atomic massof element Q is greater than that of element Z, what would be a realistic density for element Q?a.25b.30c.4d.621. Imagine that a new element, R, is discovered. It has an atomic mass of 5 amu, a density of 2 g/cm3, a melting point of 0˚C, and a boiling point of 400˚C. Where in the group of elements does R belong? a.Above element X b.Between elements Z c.Below Zd.It does not belong in the X group 22. An unknown element, A, has a density of 2.8 and aboiling point of 590oC. You are given new information that element X is an alkali metal, element Y is an alkali earth metal and element Z is a halogen. Which family would element A most likely belong to?a.Alkali metalb.Alkali Earth metalc. Halogen
23. In the same group/familyof elements the ionization energy tends to decrease as you move down the periodic table. This is due partially to thea.Decreasing size of the atom itself b.Increasing forces of attraction c.Outer electrons being closer to the nucleusd.Outer electrons being farther from the nucleus 24. Being ductile is a characteristic ofa.Metals b.Nonmetals c.Both d.Neither 25. Being non-malleableis a characteristic ofa.Metals b.Nonmetals c.Both d.Neither 26. Which of the following occurs in an ionic bond? a.Like-charged ions attract b.Two atoms share two electrons c.Two atoms share more than two electrons d.Oppositely charged ions attract (electrostatic force)27. Which of the following pairs of elements is most likely to form an ionic compound? a.Sodium and aluminum b.Oxygen and chlorine c.Nitrogen and sulfurd.Sodium and oxygen 28. In the formation of a covalent bond, electrons are a. Lost b. Gained c. Transferredd. Shared
29. Which of the following pair of elements is most likely to form a covalent compound? a.Nitrogen and oxygen b.Sodium and oxygenc.Magnesium and aluminumd.Potassium and chlorine 30.Which of the following is the best explanation of why electron geometry differs frommolecular geometry?a.Electron geometry does not take into consideration that lone pairs of electrons occupy more space than bonded pairs of electrons due to electron repulsion of the VSEPR theory.b.Molecular geometry does not take into consideration that lone pairs of electrons occupy more space than bonded pairs of electrons due to electron repulsion of the VSEPR theory.c.Electron geometry does not take into consideration that bonded pairs of electrons occupy more space than lone pairs of electrons due to electron repulsion of the VSEPR theory.d.Molecular geometry does not take into consideration that bonded pairs of electrons occupy more space than bonded pairs of electrons due to electron repulsion of the VSEPR theory.31.Which of the following is the average atomic massof Magnesium?a. 12b. 24c. 24.3d. 12.332.How many atomsare in 1 moleculeof caffeine, C8H10N4O2?a. 4b. 20c. 24d. 28
Questions 33 - 34 consists of two statements, I in the left-hand column and II in the right-hand column. For each question, determine whether statement I is true or false and whether statement II is true or false. Select the appropriate answer combination from the choices below. Choices with a check mark denote that statement II is a correct explanation (CE)of the true statement I.33. IIIH2O is polarbecauseit has polar bonds and is symmetricalIIICEATrueTrueBTrueFalseCFalseTrueDFalseFalseETrueTrue34. IIISodium has a larger atomic radius than FranciumbecauseAn atom with larger atomic radius has moreenergy levels/orbitals or a smaller positive nuclear force relative to the valence electrons. IIICEATrueTrueBTrueFalseCFalseTrueDFalseFalseETrueTrue
For questions 35 - 36, what is the correct electron structure and molecular structure name of each of the molecules?35. H2OElectron structure nameMolecular structure namea.TetrahedralBentb.TetrahedralTetrahedralc. BentTetrahedral36. NCl3Electron Structure NameMolecular Structure Namea.Trigonal PyramidTetrahedralb.TetrahedralTrigonal Pyramidc.Trigonal PlanarBentFor questions 37 - 39 Determine the correct molecular geometry and identify if the molecule is polar or nonpolar. 37. H2Oa. Polarb. Polarc. Non-polard. Non-polar38. NH3a.Polarb. Polarc. Non-polard. Non-polar
39. N2a.Polarb. Polarc. Non-polard. Non-polar40. Most of the elements in group 18 of the periodic table are known to be chemically inactive. Which of the following statements best describe why this phenomena is true.a. Group 18 elements only have 8 electrons.b. Group 18 elements are stable and unreactive so they don’t bond with other atoms.c. Group 18 elements have a full outer valence orbital.d. Group 18 elements are all gases at room temperature.Use the table below to answer questions 46Carbonhas an electronegativity of 2.6Calciumhas an electronegativity of 1.0.41.Calculate the difference in electronegativity in the Ca-C bond and identify the type of bond using the above table. a. 3.6, Ionicb. 1.6, Covalentc. -1.6, Covalentd. 1.6, Polar Covalent