chem

Which of the following compounds contains four atoms per formula unit? 0 tin(II) iodide 0 ruthenium(III) chloride 0 chromium(III) nitride 0 magnesium fluoride

ruthenium(III) chloride

Electronegativity is a concept that is useful along with other concepts in 0 formulating a statement of the octet rule 0 predicting the polarity of a bond 0 determining the charge on a polyatomic ion 0 deciding how many electrons are involved in a bond

predicting the polarity of a bond

The total number of nonbonding electron pairs present in the Lewis structure of SiH4 is one four three Zero two

zero

In a lab experiment a student heats 100.0g of Iron (III) Oxide to decompose it to 69.75g Fe and 30.25g O. The results here are an example of: the Electronegativity trend the Octet Rule Murphy's Law The Law of the Old West The Law of Constant Ions The Law of Conservation of Mass

The Law of Conservation of Mass

How many total electrons are present in a N3- ion? 10 12 7 4

10

How many grams of S are present in 29.3g of S4N4? Answer in the format Xg S 0 1.27g S 0 not enough information to determine 0 5.10g S 0 20.4g S

20.4g S

To determine the formula mass of a compound you should: 0 Add up the atomic numbers of all the atoms present 0 Add up the atomic numbers of all the atoms present and divide by the number of atoms present 0 Add up the atomic masses of all the atoms present and divide by the number of atoms present. 0 Add up the atomic masses of all the atoms present.

Add up the atomic masses of all the atoms present.

Which of the following statements contrasting covalent bonds and ionic bonds is correct? 0 Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal. 0 Covalent bonds usually involve a metal and a nonmetal and ionic bonds usually involve two nonmetals. 0 Covalent bonds usually involve two nonmetals and ionic bonds usually involve two metals. 0 Covalent bonds usually involve two metals and ionic bonds usually involve a metal and a nonmetal.

Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal.

Which of the following statements is an accurate description of the structure of the ionic compound LiBr? 0 Each cation present is surrounded by six anions in an extended array 0 Individual molecules containing a Li+ ion and a Br- ion are present 0 Alternating layers of Li and Br atoms are present 0 Clusters of Li+ ions are balanced out by clusters of Br- ions

Each cation present is surrounded by six anions in an extended array

For representative elements, valence electrons are those electrons located In the outermost subshell. In s orbitals. Closest to the nucleus In the outermost shell

In the outermost shell

Which of the following statements about polyatomic ions is correct? 0 All carry a charge of two. 0 Negative ions are more common than positive ions. 0 All must contain one of the halogens. 0 Negative ions are more common than positive ions.

Negative ions are more common than positive ions.

The lowest whole-number molar ratio of elements in a compound is termed: 0 The empirical formula 0 The secret formula 0 The molecular formula 0 The ratio formula

The empirical formula

In which of the following molecules is a coordinate covalent bond present? a. H-C≡N b. O=C=O c. N≡N d. N≡N-O

a H-C≡N

Which of following statements concerning theoretical yield, actual yield, and percent yield is correct? a Theoretical yield is a calculated number. b Actual yield is a calculated number. c A percent yield of greater than 50% is very difficult to obtain. d. Percent yield is calculated by dividing the theoretical yield by the actual yield.

a Theoretical yield is a calculated number.

What is the geometry of the molecular compound H2S? linear trigonal planar angular (bent) tetrahedral

angular (bent)

The "octet rule" relates to the number eight because 0 all electron subshells can hold eight electrons. 0 only atoms with eight valence electrons undergo chemical reaction. 0 atoms, during compound formation, frequently obtain eight valence electrons. 0 ions with charges of +8 and -8 are very stable.

atoms, during compound formation, frequently obtain eight valence electrons.

In which of the following pairings is the chemical formula not consistent with the ions shown? a. M2+, X3-, M3X2 b. M2+, X-, MX2 c. M+, X3-, MX3

b M2+, X-, MX2

Which of the following linear molecules is a nonpolar molecule containing polar bonds? a H-C≡N b O=C=O c H-Cl d N≡N

b O=C=O

Which of the following compounds contains both ionic and covalent bonds? a. SiO2 b. LiI c. LiCN d. PCl3

b. LiI

A mole of a chemical substance represents athe mass of the substance that will combine with 12.0 g of carbon b the mass of the substance that will combine with 100.0 g of oxygen c 6.02 × 1023 chemical particles of the substance d 6.02 × 10-23 grams of the substance

c 6.02 × 1023 chemical particles of the substance

In which of the following pairs of compounds are both members of the pair ionic compounds? a. PI3 and HBr b. H2S and NCl3 c. LiI and NiO d. LiF and H2O

c LiF and NiO

Which of the following ions is not isoelectronic with the noble gas neon? a. Na+ b. F- c. N3- d. Cl-

c n3-

Which of the following samples contains the greatest number of atoms? a. 9 mole of CO2 b. 10 moles of Xe c. 11 moles of N2O d. 12 moles of CO

c. 11 moles of N2O

For which of the following pairs of compounds do both members of the pair have names that contain the prefix di-? a SCl2 and K2O b CO2 and N2O c N2O3 and H2S d more than one correct response e no correct response

d more than one correct response

Sixteen electrons are present in the Lewis structure of which of the following molecules? a CO2 b N2O c SO2 d more than one correct response e no correct response

d more than one correct response

How many grams of H2O will be produced from 21.0g of O2 and an excess of H2S according to the reaction 2H2S + 3O2 --> 2H2O + 2SO2 a. 7.88g H2O b. 17.7g H2O c. 15.76g H2O d. 8.01g H2O

d. 8.01g H2O

Draw Lewis structures for the following molecules or ions. Which is nonpolar? a. H2O b. NH3 c. N2O d. CH4

d. CH4

Which of the following chemical equations is balanced?a. 2H2 + O2 → H2O b. 2SO2 + 2 O2 → 3 SO3 c. KClO3 → KCl + 3 O2 d. N2 + 3H2 → 2NH3

d. N2 + 3H2 → 2NH3