AP Chem Unit 2

Which of the following compounds contains both ionic and covalent bonds? A SO3 B C2H5OH C MgF2 D H2S E NH4Cl

E. NH4Cl

The molecule with the largest dipole moment A CO2 B H2O C CH4 D C2H4 E PH3

B. H2O

Based on the Lewis diagram for NH3 shown, the H-N-H bond angle is closest to which of the following? 60° 90° 109.5° 120°

109.5°

How many sigma and pi bonds are present in the following molecule? 8 sigma bonds and 1 pi bond 8 sigma bonds and 2 pi bonds 10 sigma bonds and 2 pi bonds 11 sigma bonds and 2 pi bonds 11 sigma bonds and 1 pi bond

11 sigma bonds and 1 pi bond

On the basis of the information above, which of the following arranges the binary compounds in order of increasing bond polarity? A CH4 < SiCl4 < SF4 B CH4 < SF4 < SiCl4 C SF4 < CH4 < SiCl4 D SiCl4 < SF4 < CH4

A. CH4 < SiCl4 < SF4

H - C ≡ C - H What is the hybridization of the carbon atoms in a molecule of ethyne, represented above? A sp B sp2 C sp3 D dsp2 E d2sp

A. sp

Which of the following statements, if true, would support the claim that the NO3− ion, represented above, has three resonance structures? A The NO3− ion is not a polar species. B The oxygen-to-nitrogen-to-oxygen bond angles are 90°. C One of the bonds in NO3− is longer than the other two. D One of the bonds in NO3− is shorter than the other two.

A. the NO3- ion is not a polar species

Reaction 1: CaC2(s) + 2 H2O(l) → C2H2(g) + Ca(OH)2(s) Reaction 2: NaOCl(aq) + 2 HCl(aq) → Cl2(g) + NaCl(aq) + H2O(l) Reaction 3: C2H2(g) + Cl2(g) → C2H2Cl2(g) When Reaction 3 occurs, does the hybridization of the carbon atoms change? A Yes; it changes from sp to sp2. B Yes; it changes from sp to sp3. C Yes; it changes from sp2 to sp3. D No; it does not change

A. yes, it changes from sp to sp2

The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+. II. O2- is more negatively charged than F-. III. The O2- ion is smaller than the F- ion. A II only B I and II only C I and III only D II and III only

B I and II only

The particulate-level diagram shown above best helps to explain which of the following properties of ionic solids? A) Density B) Brittleness C) Malleability D) Conductivity

B) Brittleness

Which of the following claims about a binary compound composed of elements with the same electronegativity is most likely to be true? A)The compound has properties similar to those of both elements. B) The bonding in the compound is nonpolar covalent. C) The boiling point of the compound is above 1000 °C. D) The compound contains strong ionic bonds.

B) The bonding in the compound is nonpolar covalent.

which of the following lewis dot diagrams describe the molecules that are the most polar? A. ClF B. BrF 3. CS2 D. BF3

B. BrF

Has a trigonal-pyramidal molecular geometry A H2O B NH3 C BH3 D CH4 E SiH4

B. NH3

Resonance is most commonly used to describe the bonding in molecules of which of the following? A CO2 B O3 C H2O D CH4 E SF6

B. O3

Is a polar molecule A BeCl2 B SO2 C N2 D O2 E F2

B. SO2

A particle-level diagram of a metallic element is shown above. Typically, metals are both malleable and ductile. The best explanation for these properties is that the electrons involved in bonding among metal atoms are A unequally shared and form nondirectional bonds B unequally shared and form highly directional bonds C equally shared and form nondirectional bonds D equally shared and form highly directional bonds

C equally shared and form nondirectional bonds

The lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions largest? (Assume that the distance between the ions in each pair is equal to the sum of the ionic radii.) A. NaCl B. CaBr C. MgO D. CaO

C. MgO

the energy required to dissociate an ionic solid into gaseous ions (lattice energy) for the compounds NaF and MgF2 is shown in the table above. On the basis of Coulomb's law, which of the following best helps to explain the large difference between the lattice energies of NaF and MgF2 ? A The solubility of MgF2 is less than that of NaF. B The electronegativity of Mg is greater than that of Na. C The mass of the Mg cation is greater than that of the Na cation. D The charge of the Mg cation is larger than that of the Na cation.

D The charge of the Mg cation is larger than that of the Na cation.

On the basis of electronegativity differences between atoms, which of the following scientific claims is the most accurate regarding the bonding in Mg(NO3)2? A There is polar covalent bonding between Mg atoms and N atoms. B There is polar covalent bonding between Mg and O atoms. C There is ionics bonding between N5+ ions and O2- ions. D There is ionic bonding between Mg2+ ions and NO3- ions.

D There is ionic bonding between Mg2+ ions and NO3- ions.

Which of the following claims about a binary compound in which the bonding is ionic is most likely to be scientifically valid? A) Both elements in the compound are metals. B) The atomic masses of the elements in the compound are relatively small. C) There is equal sharing of electrons between the atoms of the elements in the compound. D) The electronegativity difference between the elements in the compound is relatively large.

D) The electronegativity difference between the elements in the compound is relatively large.

20. Which of the molecules represented below contains carbon with sp2 hybridization? A CH4 B CH2Cl2 C C2H6 D C2H2Cl2 E C2H4Cl2

D. C2H2Cl2

Which of the following molecules contains polar covalent bonds but is a nonpolar molecule? A CH3Cl B CH2Cl2 C NH3 D CCl4 E N2

D. CO4

Which of the diagrams above best represents the CH2O molecule, and why? Diagram 1, because all bond angles are 180°. Diagram 1, because all atoms have a formal charge of 0. Diagram 2, because the molecule has a trigonal pyramidal shape. Diagram 2, because all atoms have a formal charge of 0.

Diagram 2, because all atoms have a formal charge of 0.

Which of the following has a zero dipole moment? A HCN B NH3 C SO2 D NO2 E PF5

E PF5

Which of the following indicates whether the solid substance represented by the particulate diagram shown above conducts electricity and explains why or why not? It conducts electricity because it is made of positive and negative particles. It conducts electricity because electrons are free to move through the substance. It does not conduct electricity because electrons are strongly attracted to specific positive particles. It does not conduct electricity because the positive particles are not free to move through the substance.

It conducts electricity because electrons are free to move through the substance.

Which of the following correctly indicates whether the solid represented by the particulate model shown above conducts electricity and explains why or why not?

It does not conduct electricity because its ions cannot move freely within the solid.

Which molecule is correctly matched with its shape as predicted by VSEPR theory? PCl3 - trigonal pyramidal OF2 - linear ClF3 - trigonal planar SF6 - hexagonal

PCl3 - trigonal pyramidal

The elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from C and Se is most likely to be true? A The carbon-to-selenium bond is unstable. B The carbon-to-selenium bond is nonpolar covalent. C The compound has the empirical formula CSeCSe. D A molecule of the compound will have a partial negative charge on the carbon atom.

b. the carbon-to-selenium bond is nonpolar covalent

Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound? A It has the formula XZ2. B It does not dissolve in water. C It contains ionic bonds. D It contains covalent bonds.

c. it contains ionic bonds

The hybridization of the carbon atoms in CH6 can be described as A sp B sp2 C sp3 D dsp2 E d2sp

c. sp3

The molecular shape of BrF3 is: a. trigonal bipyramidal b. see-saw c. t-shaped d. linear e. trigonal planar

c. t-shaped

structure of steel

carbon atoms are between iron atoms

The molecule with only one double bond A CO2 B H2O C CH4 D C2H4 E PH3

d. c2h4

Which of the following scientific claims about the bond in the molecular compound HF is most likely to be true? A There is a partial negative charge on the H atom. B Electrons are shared equally between the H and F atoms. C The bond is extremely weak. D The bond is highly polar.

d. the bond is highly polar