IB Chem: Topic 4.3 Practice Questions

B. I and III only

C₆₀ fullerene consists of a simple molecular structure. Silicon dioxide, SiO₂, can be described as a giant covalent (macromolecular) structure. Which statements are correct? I. Each carbon atom in C₆₀ fullerene is bonded in a sphere of 60 carbon atoms, consisting of pentagons and hexagons. II. Each O-Si-O bond angle in is 180°. III. SiO₂ is insoluble in water. A. I and II only B. I and III only C. II and III only D. I, II and III

A. I and II only

Diamond, C₆₀ fullerene and graphite are allotropes of carbon. Which statements are correct about these allotropes? I. In diamond each carbon is held in a tetrahedral arrangement. II. In C₆₀ fullerene each carbon is held in a trigonal arrangement. III. In graphite each carbon is held in a tetrahedral arrangement. A. I and II only B. I and III only C. II and III only D. I, II and III

A. Network covalent

A substance has the following properties: What is the most probable structure of this substance? A. Network covalent B. Polar covalent molecule C. Ionic lattice D. Metallic lattice

B. 109°, giant molecule

What are the approximate bond angles and structure of crystalline SiO₂?

C. Giant molecular

26. [1 mark] A solid has a melting point of 1582 °C and does not dissolve in water. It does not conduct electricity in the molten state. What type of structure does the solid have? A. Ionic B. Metallic C. Giant molecular D. Simple molecular

D. H₂O < NH₃ < CH₄

How do the bond angles in CH₄, NH₃ and H₂O compare?

B. 4, 3, 3

How many atoms is each carbon directly bonded to in its allotropes?

C. 2

How many non-bonding pairs of electrons are there in a nitrogen molecule? A. 0 B. 1 C. 2 D. 3

D. The ion has a trigonal pyramidal shape.

Lewis structures are represented in different ways in different parts of the world. Two ways of drawing the Lewis structure for H₃O⁺ are shown below. Which statement is correct about H₃O⁺? A. The ion has a tetrahedral shape. B. The H-O-H bond angle is 120°. C. The H-O-H bond angle is 90°. D. The ion has a trigonal pyramidal shape.

D. 109.5°, 104.5°, 120°

The Lewis (electron dot) structure of aspirin is represented below. What are the approximate values of the bond angles α, β, and γ, in the molecule? A. 90°, 104.5°, 104.5° B. 90°, 120°, 120° C. 109.5°, 120°, 120° D. 109.5°, 104.5°, 120°

A. 104.5°, 120°, 109.5°

The Lewis (electron dot) structure of paracetamol (acetaminophen) is pictured. What are the approximate values of the bond angles α, β, and γ ? A. 104.5°, 120°, 109.5° B. 109.5°, 109.5°, 109.5° C. 120°, 120°, 90° D. 104.5°, 120°, 90°

A. Bent (V-shaped)

The Lewis structure of SO₂ is given below. What is the shape of the SO₂ molecule? A. Bent (V-shaped) B. Linear C. T-shaped D. Triangular planar

B. trigonal planar and tetrahedral

What are the predicted electron domain geometries around the carbon and both nitrogen atoms in urea, (NH₂)₂CO, applying VSEPR theory?

A. Allotropes

What describes the relationship between diamond, graphite and C₆₀ fullerene? A. Allotropes B. Isomers C. Isotopes D. Polymers

D. tetrahedral, 4, tetrahedral, 4

What describes the structure of silicon and silicon dioxide?

B. 107°

What is the bond angle in the H₃O⁺ ion? A. 104° B. 107° C. 109° D. 120°

B. trigonal planar 120°

What is the molecular geometry and bond angle in the molecular ion NO₃⁻?

D. Trigonal planar, 120°

What is the shape and the bond angle of the molecule BF₃?

B. Trigonal pyramidal

What is the shape of the ammonia molecule, NH₃? A. Trigonal planar B. Trigonal pyramidal C. Linear D. V-shaped (bent)

A. covalent, high mp, covalent, high mp

Which combination best describes the type of bonding present and the melting point of silicon and silicon dioxide?

D. 4, tetrahedral, trigonal pyramidal, 107°

Which combination describes the sulfate(IV) ion, SO₃²⁻(also known as sulfite ion)?

C. bent (v-shaped), 119°

Which combination of shape and bond angle best describes a molecule of sulfur dioxide, SO₂?

D. SiO₂ (s)

Which compound has a covalent macromolecular (giant covalent) structure? A. MgO(s) B. Al₂O₃ (s) C. P₄O₁₀ (s) D. SiO₂ (s)

D. Na₂CO₃

Which compound has resonance structures? A. C₆H₁₂ B. CH₃CHO C. NaBr D. Na₂CO₃

B. London forces, dipole-dipole, hydrogen bonding

Which correctly states the strongest intermolecular forces in the compounds below?

A.

Which diagram represents the bonding in SiO₂?

C. II and III only

Which diagrams can be used to represent the Lewis (electron dot) structure of boron trifluoride? A. I and II only B. I and III only C. II and III only D. I, II and III

C. Diamond

Which form of carbon is the poorest electrical conductor? A. Graphite B. Graphene C. Diamond D. Carbon nanotube

C. C₆H₆, CO₃²⁻ and graphite

Which group of ions and molecules has delocalized electrons in all the species? A. CH₃COCH₃, C₂H₅COO⁻ and O₃ B. NO₃⁻, NO₂⁻ and CO₂ C. C₆H₆, CO₃²⁻ and graphite D. C₆H₆, CO₃²⁻ and C₂H₂

A. Each silicon atom forms four single covalent bonds to oxygen atoms.

Which is the best description of the bonding present in silicon dioxide, SiO₂? A. Each silicon atom forms four single covalent bonds to oxygen atoms. B. Each silicon atom forms two double covalent bonds to oxygen atoms. C. Each silicon atom forms two single covalent bonds to oxygen atoms. D. Each silicon atom forms four double covalent bonds to oxygen atoms.

A. H₂C=CH₂

Which is the correct Lewis structure for ethene, C₂H₄?

C. C₂H₄

Which molecule contains a bond angle of approximately 120°? A. CH₄ B. C₂H₂ C. C₂H₄ D. C₂H₆

D. CO

Which molecule contains a dative covalent (coordinate) bond? A. HCN B. H₂O₂ C. CO₂ D. CO

B. SO₂

Which molecule has a non-bonding (lone) pair of electrons on the central atom? A. BF₃ B. SO₂ C. CO₂ D. SiF₄

A. SF₆

Which molecule has an octahedral shape? A. SF₆ B. PCl₅ C. XeF₄ D. BF₃

A. CH₂Cl₂

Which molecule is polar? A. CH₂Cl₂ B. BCl₂ C. Cl₂ D. CCl₄

C. NH₃ and HF

Which molecules react to form a dative covalent (coordinate) bond? A. CH₄ and NH₃ B. C₂H₂ and Cl₂ C. NH₃ and HF D. Cl₂ and HF

A. CH₄ and NH₄⁺

Which pair has the same bond angles? A. CH₄ and NH₄⁺ B. NH₃ and H₂O C. C₂H₄ and C₂H₂ D. CO₂ and SO₂

D. CCl₄ and SiH₄

Which pair of molecules has the same bond angles? A. PCl₃ and BCl₃ B. SO₂ and CO₂ C. H₂O and NH₃ D. CCl₄ and SiH₄

A. covalent, high mp, covalent, low mp

Which row correctly describes the bonding type and melting point of carbon and carbon dioxide?

B. I and III only

Which species contain a dative covalent (coordination or coordinate) bond? I. Carbon monoxide, CO II. Ammonia, NH₃ III. Oxonium ion, H₃O⁺ (aka. hydronium ion) A. I and II only B. I and III only C. II and III only D. I, II and III

C. II and III only

Which species contain a dative covalent bond? I. HCHO II. CO III. H₃O⁺ A. I and II only B. I and III only C. II and III only D. I, II and III

B. I and III only

Which species contain dative covalent bonds? I. CO II. NH₃ III. H₃O⁺ A. I and II only B. I and III only C. II and III only D. I, II and III

C. NCl₃

Which species contains a bond angle of approximately 107°? A. H₂O B. CF₄ C. NCl₃ D. BF₃

D. CO

Which species contains a dative covalent (coordinate) bond? A. HCN B. C₂H₂ C. CO₂ D. CO

B. CH₃OH

Which species has the longest carbon to oxygen bond length? A. CO B. CH₃OH C. CH₃CO₂⁻ D. H₂CO

C. Ionic solids are always brittle.

Which statement about the physical properties of substances is correct? A. The only solids that conduct electricity are metals. B. All substances with covalent bonds have low melting points. C. Ionic solids are always brittle. D. All metals have high densities.

D. I, II and III

Which statements about graphite are correct? I. Carbon atoms are held in layers with weak attractions between layers. II. Graphite is a non-metal which conducts electricity. III. Each carbon atom is covalently bonded to three other carbon atoms. A. I and II only B. I and III only C. II and III only D. I, II and III

A. giant covalent, each O is covalently bonded to two Si atoms.

Which statements about the structure and bonding of silicon dioxide are correct?

D. 1710, low, none

Which substance has a giant covalent structure?

A. Glucose, C₆H₁₂O₆

Which substance has the following properties? • Low melting point • Very soluble in water • Does not conduct electricity when molten A. Glucose, C₆H₁₂O₆ B. Silicon dioxide, SiO₂ C. Sodium chloride, NaCl D. Tetrachloromethane, CCl₄