CHEM 108 - Homework 6
linear / linear
lewis structure of ethyne (C₂H₂) & the appropriate pair of molecular geometries of the two central atoms
tetrahedral / bent
lewis structure of methanol (CH₃OH) & the appropriate pair of molecular geometries of the two central atoms
2, 3, 2
what numbers belong in the blank spaces to fully balance the following reaction? __Fe (s) + __Cl₂ (g) → __FeCl₃ (s)
NH₃ it is a polar molecule & can form H bonds; other molecules are nonpolar & their intermolecular forces are dispersion forces; NH₃ has the strongest intermolecular forces & the highest BP
which of the following would you expect to have the highest boiling point? a) H₂ b) NH₃ c) N₂
C(s) + O₂(g) → CO₂(g)
write a balanced chemical equation based on the following description: the reaction of solid carbon with oxygen gas to form carbon dioxide gas
dispersion forces I₂ is a homonuclear diatomic molecule－cannot be ionic & cannot have a dipole; the only possible intermolecular forces it can experience are dispersion forces (experienced by any species w/ electrons)
the predominant intermolecular force between molecules of I₂ is
dispersion forces & dipole-dipole interactions NO₂ is a polar molecule & because it has a net dipole it will experience dipole-dipole interactions; all molecules experience dispersion forces
in a pure sample of NO₂, what forces of attraction exist between the molecules?
tetrahedral / trigonal pyramidal
lewis structure of PH₃ & then determine its electron domain & molecular geometries
I, II, and III H₂O is a polar molecule, & has a H bonded to an O; all 3 types of intermolecular forces are possible for water molecules
which of the following intermolecular forces are present in a pure sample of H₂O? I. dispersion forces II. dipole-dipole interactions III. hydrogen bonding
CH₃OH for molecules of approx. the same size, the strength of the intermolecular forces present will be the best predictor of the boiling point; CH₃OH is a polar molecule that forms H bonds, while the strongest intermolecular forces in the other molecules are dipole-dipole attraction or dispersion forces; H bonding is a strong intermolecular force
which of the following is expected to have the highest boiling point? a) CH₄ b) CH₃Cl c) CH₃OH
2 K₃PO₄(aq) + 3 NiBr₂(aq) → Ni₃(PO₄)₂(s) + 6 KBr(aq)
write a balanced chemical equation based on the following description: aqueous potassium phosphate reacts with aqueous nickel(II) bromide to produce solid nickel(II) phosphate and aqueous potassium bromide
II only all polar molecules experience dipole-dipole interactions; CO₂ is a linear symmetrical molecule & is nonpolar; HCl is a linear asymmetrical molecule & is polar; CCl₄ is a symmetrical tetrahedral molecule & is nonpolar
as a pure substance, which of the following could experience dipole-dipole interactions? I. CO₂ II. HCl III. CCl₄
II only for hydrogen bonding to be present, a H atom needs to be bonded to N, O, or F; H₂O is the only option that meets this criteria & that can form hydrogen bonds; hydrogen bonding is a strong type of dipole-dipole interaction that results from H being covalently bonded to a very electronegative atom (N, O, or F); it is a very strong intermolecular force
as a pure substance, which of the following could experience hydrogen bonding? I. H₂Se II. H₂O III. H₂
Al₂(SO₄)₃ (aq) + 2 K₃PO₄ (aq) → 2 AlPO₄ (s) + 3 K₂SO₄ (aq)
balance the following chemical reaction: Al₂(SO₄)₃ (aq) + K₃PO₄ (aq) → AlPO₄ (s) + K₂SO₄ (aq)
Fe₂S₃ (s) + 6 HCl (g) → 2 FeCl₃ (s) + 3 H₂S (g)
give the balanced equation for solid iron(III) sulfide reacting with gaseous hydrogen chloride to form solid iron(III) chloride and hydrogen sulfide gas
tetrahedral / tetrahedral
lewis structure of CBr₄ & then determine its electron domain & molecular geometries
polar
lewis structure of CH₃F & then determine if the molecule is polar or nonpolar
nonpolar
lewis structure of O₂ & then determine if the molecule is polar or nonpolar
nonpolar
lewis structure of carbon dioxide (CO₂) & then determine if the molecule is polar or nonpolar
linear / linear
lewis structure of silicon dioxide (SiO₂) & then determine its electron domain & molecular geometries
tetrahedral / bent
lewis structure of water (H₂O) & then determine its electron domain & molecular geometries
HCl < HBr < HI < HF BP is the temp. at which a substance will change from the liquid phase→gas phase, so compounds w/ stronger intermolecular forces will have ↑ BP; HF can form H bonds－strongest intermolecular forces & highest BP; other compounds are all polar & exhibit dipole-dipole & dispersion forces which are higher for molecules w/ more electrons; HCl (18e-), HBr (36e-), HI (54e-), HF (8e-) but its ability to form H bonds results in a ↑ BP
rank the following compounds in order of lowest boiling point to highest boiling point based on intermolecular forces a) HF < HCl < HBr < HI b) HI < HBr < HCl < HF c) HCl < HBr < HI < HF
3, 2
what are the coefficients in front of the H₂ & the Au if you balance the following unbalanced equation: Au₂S₃ + H₂ → Au + H₂S
trigonal pyramidal (pyramidal) ammonia has 3 groups & 1 set of lone pairs bound to a central atom
what is the correct molecular geometry of NH₃ according to Valence Shell Electron Pair Repulsion Theory
6 C₄H₉OH + 6 O₂ → 4 CO₂ + 5 H₂O
when butanol (C₄H₉OH) is burned in oxygen, CO₂ & H₂O are the products; what is the coefficient in front of the O₂ in the balanced equation (using only whole numbers & the lowest whole number ratio)
N₂(g) + 3 H₂(g) → 2 NH₃(g)
write a balanced chemical equation based on the following description: gaseous nitrogen and hydrogen react to form gaseous ammonia
N₂(g) + O₂(g) →2 NO(g)
write a balanced chemical equation based on the following description: nitrogen gas and oxygen gas react to produce nitrogen monoxide gas
trigonal planar / trigonal planar
lewis structure of BH₃ & then determine its electron domain & molecular geometries
BaCO₃(s) → BaO(s) + CO₂(g)
write a balanced chemical equation based on the following description: solid barium carbonate decomposes into solid barium oxide and carbon dioxide gas when heated
2 Cr(s) + 3 I₂(s) → 2 CrI₃(s)
write a balanced chemical equation based on the following description: solid chromium reacts with solid iodine to form solid chromium(III) iodide
S(s) + O₂(g) → SO₂(g)
write a balanced chemical equation based on the following description: solid sulfur and oxygen gas react to produce sulfur dioxide gas
2 Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2 Fe(l)
write a balanced chemical equation based on the following description: the reaction of powdered aluminum and powdered iron(III) oxide produces solid aluminum oxide and liquid iron metal
2 KClO₃ (s) → 2 KCl (s) + 3 O₂ (g)
write the balanced equation for the reaction of solid potassium chlorate decomposing to form solid potassium chloride and oxygen gas
