Student Name:___________________________________
Topic 1: Covalent Bonding Homework A) Multiple Choice Questions: Place your answer in the space in front of each question. _____1) When two atoms of nitrogen bond, how many pairs of electrons will be shared between them? a) 1 b) 2 c) 3 d) 4 _____2) When two atoms of fluorine bond, how many electrons will be shared between them? a) 1 b) 2 c) 3 d) 4 _____3) When an atom of H and an atom of F bond together: a) The H will be partially positive, because it has higher electronegativity than F. b) The H will be partially negative, because it has higher electronegativity than F. c) The F will be partially positive, because it has higher electronegativity than H. d) The F will be partially negative, because it has higher electronegativity than H. _____4) Which of the molecules listed below has the most polar bond between the bonded atoms, in terms of greatest END? a) HF b) HCl c) HBr d) HI _____5) Which of the following compounds is formed by covalent bonding? a) Na2S b) AlCl3 c) C6H12O6 LiH
d)
_____6) Which of the following molecules contains a nonpolar covalent bond? a) H2O b) HF c) F2 d) NH3 _____7) Which of the following molecules contains a polar covalent bond? a) H2 b) PH3 c) F2 d) NH3
Adapted from © 2008, Mark Rosengarten
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B) Identify the following bonds as being polar covalent or nonpolar covalent. For the polar covalent bonds, label the + and - ends.
Bond
END
Polar or Nonpolar?
If polar, label the ends
H – C H – Cl C – Cl P – Cl Cl – Cl H – P H – O O – O
+
H–C H – Cl C – Cl P – Cl Cl – Cl H–P H–O O–O
C) Explain, in terms of electronegativity difference, why Cl2 contains nonpolar covalent bonds.
) Explain, in terms of electronegativity difference, why H2O contains polar covalent bonds.
Adapted from © 2008, Mark Rosengarten
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and
-
Students Name _______________________________________ Homework # 2
A)
Complete the following chart, drawing the dot diagram of each element in the molecule and then the dot diagram of the molecule. If the formula is H2O, make sure you have two atoms of H and one of O in your dot diagram of the molecule. Formula
F2 HBr
Dot diagram for: F
Dot diagram for: F
H
Br
H
O
N
H
H
S
C
H
Dot Diagram of Molecule
Shape
H2O NH3
H2S CH4
Adapted from © 2008, Mark Rosengarten
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Students Name_______________________________________
Homework # 3
Molecular Substances Homework
A) Multiple Choice Questions: Place your answer in the space in front of each question.
_____1) Which of the following molecules is polar? a) F2 b) NH3 c) O2
d) Cl2
_____2) Which of the following molecules has the strongest hydrogen-bond attractions? a) HF b) HCl c) HBr d) HI _____3) Which of the following nonpolar molecules has the highest boiling point? a) CH4 b) C2H6 c) C3H8 d) C4H10 _____4) Which of the following molecules is a liquid at STP? a) N2 b) H2 c) Br2 d) I2 _____5) Which of the following molecules is bent? a) N2 b) H2O c) NH3
d) CCl4
_____6) Which of the following molecules is pyramidal? a) N2 b) H2O c) NH3
d) CCl4
_____7) Which of the following molecules is tetrahedral? a) N2 b) H2O c) NH3
d) CCl4
_____8) Which of the following substances is molecular? a) NaCl b) CO2 c) K2O
Adapted from © 2008, Mark Rosengarten
d) C
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B) For each of the following molecules represented by structural formulas indicate
a) if the molecule is polar or nonpolar. b) If polar, draw the dipole moment and which side is partially positive and which side is partially negative. If nonpolar, then skip this step and move on to c). c) Identify the shape of the molecule d) identify the type of attractive force that will hold molecules of this substance together in the liquid and solid phase. Molecule (do B in this box)
Polar or Nonpolar
Shape
IMAF Type
Dot Diagram
H – Cl H–H H–O | H H-N–H | H
Cl | Cl – C – Cl | Cl
O=C=O
H - Br
Adapted from © 2008, Mark Rosengarten
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Name_______________________
Homework #4 Molecular Formulas and Naming Homework A) Multiple Choice Questions: Place your answer in the space in front of each question. _____1) Which of the following is an empirical formula? a) H2O2 b) CaCO3 c) C2H4
d) C6H12O6
_____2) Which of the following is a molecular formula? a) H2O2 b) CaCO3 c) CH4
d) CO2
_____3) What is the empirical formula of C4H10? a) C4H10 b) C2H5 c) CH5
d) CH2
_____4) How many moles of oxygen atoms are there in 2 moles of C6H12O6? a) 6 b) 12 c) 24 d) 48 B) Determine the molecular formulas for each question below, showing all work. 1) The empirical formula of a compound is found to be CH, and the molecular mass has been determined to be 78.0 g/mole. What is the molecular formula of this compound?
2) The empirical formula of a compound is found to be HO, and the molecular mass has been determined to be 34.0 g/mole. What is the molecular formula of this compound?
3) The empirical formula of a compound is found to be NO2, and the molecular mass has been determined to be 92.0 g/mole. What is the molecular formula of this compound?
Adapted from © 2008, Mark Rosengarten
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C) Identify each of the following as an empirical or molecular formula. If a formula is molecular, write its empirical formula. Formula
Empirical or Molecular?
Simplify if Molecular
Formula
Empirical or Molecular?
NaCl
N2O4
C2H6
Ra(CN)2
Ba(NO3)2
C6H12O6
Simplify if Molecular
C) Fill in the blanks for each molecular compound, using the clue given for each:
Formula
Name (Stock System)
Name (Prefix System)
SO3 Phosphorous (V) oxide Phosphorous trichloride H2O Hydrogen nitride Carbon tetrabromide HCl Hydrogen sulfide
Adapted from © 2008, Mark Rosengarten
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