Master Compound Questions for DAT Exam Success

III. Compound theory questions

Compound questions

There are a total of 41 compound questions, which are important content-oriented in the summary part of this chapter. Approximately 1 minute is given per question in each test. After the test, if you press the “See Result” button, the results will be displayed along with the answer choices. Red marks indicate incorrect answers and green marks indicate correct answers. Explanations or solutions to the questions are displayed below each question.

COMPOUND THEORY TEST 1

1 / 20

Which of the following is an example of a polyatomic anion?

A. PO₄^3- : Phosphorous

B. ClO^2- : Hypochlorate

C. BrO₃^– : Bromate

D. BrO₄^– : Bromine tetraoxide

E. SO₄^2- : Sulfite

Explanation:

PO₄³^– : Phosphate

ClO^– : Hypochlorite

BrO₄^–: Perbromate

SO₄²^– : Sulfate

2 / 20

Which of the following acids is INCORRECTLY named?

A. HCl : Hydrochloric acid

B. HNO₂ : Nitrous acid

C. HNO₃ : Nitric acid

D. HClO₄ : Perchloric acid

E. H₂SO₃ : Sulfuric acid

Explanation:

H₂SO₃ : Sulfurous acid

3 / 20

Which of the following compounds is INCORRECTLY named?

A. CaCl₂ : Calcium chloride

B. Ba₃(PO₄)₂ : Barium phosphate

C. SnF₄ : Tin(IV) fluoride

D. P₂O₅ : Diphosphorus pentoxide

E. CuCrO₄ : Copper(IV) chromate

Explanation:

CrO₄²^– is a double charged anion. Cu²⁺+ CrO₄²^– → Cu₂(CrO₄)₂ → CuCrO₄. Therefore, CuCrO₄ is Copper(II) chromate.

4 / 20

Which of the following compounds is correctly named?

A. PCl₃ : Phosphorus chloride

B. SO₄^2- : Sulfite ion

C. HCN : Hydrocyanic acid

D. Ca(ClO)₂ : Calcium(II) hypochloride

E. SeO₂ : Selenium(II) oxide

Explanation:

PCl₃ : Phosphorus trichloride

SO₄²^– : Sulfate ion

Ca(ClO)₂ : Calcium hypochloride

SeO₂ : Selenium dioxide

5 / 20

Which of the following is the correct chemical formula for magnesium carbonate?

A. MgCO

B. MgCO₃

C. Mg₂CO₃

D. Mg(CO₃)₂

E. Mg₂(CO₃)₂

Explanation:

Magnesium carbonate: Mg²⁺+ (CO₃)^2- → Mg₂(CO₃)₂ → MgCO₃

6 / 20

What type of bonding is in the compound CaCl₂?

A. Covalent bonding

B. Ionic bonding

C. Hydrogen bonding

D. Metallic bonding

E. B and D

Explanation:

Attraction of opposite charges between the metal atom (Ca²⁺) and the nonmetal atom (Cl^–) is called ionic bond.

7 / 20

Which of the following molecules would be expected to have the highest lattice energy?

A. AlCl₃

B. MgCl₂

C. KI

D. MgBr₂

E. KBr

Explanation:

Lattice energy is the force required to break ionic bonds. The smaller size of metal and nonmetal atoms, the greater lattice energy.

8 / 20

Choose the correct statement(s) for ionic bonds.

I. Forming bonds by transferring electrons between two elements.

II. Forming bonds by sharing electrons between two elements.

III. Chemical bonds between metal and nonmetal elements.

IV. Chemical bonds between nonmetal elements.

V. Higher polarity and easy solving in polar solvents.

A. II only

B. I and III

C. II and IV

D. II, IV, and V

E. I, III, and V

Explanation:

Ionic bonds are held together by transferring an electron between metal and nonmetal elements such as NaCl or LiF. They have usually higher polarity and solve easily in polar solvents.

9 / 20

Choose the correct statement(s) for covalent bonds.

I. Forming bonds by transferring electrons between two elements.

II. Forming bonds by sharing electrons between two elements.

III. Chemical bonds between metal and nonmetal elements.

IV. Chemical bonds between nonmetal elements.

V. Higher polarity and easy solving in polar solvents.

A. II only

B. I and III

C. II and IV

D. II, IV, and V

E. I, III, and V

Explanation:

Covalent bonds are formed by sharing electrons between their nonmetal elements such as Cl₂ or CH₄. These bonds have a weaker polarity than ionic bonds.

10 / 20

Choose the INCORRECT statement for metallic bonds.

A. Attraction force by delocalized electrons.

B. High conduction of heat and electricity.

C. High melting and boiling point.

D. Easily brittle in the solid state.

E. Chemical bonds between single metallic atoms.

Explanation:

Except for D, all these statements are true of metallic bonds. Ionic bonds, not metallic bonds, are easily brittle in the solid state.

11 / 20

Which of the following molecules has the triple bond?

A. CO₂

B. HCN

C. Br₂

D. NH₃

E. N₂

Explanation:

Br₂ and NH₃ have single bonds and CO₂ and N₂ have double bonds.

12 / 20

Which of the following bonds are INCORRECTLY matched to their molecular compounds?

A. Polar bonds: HF, LiF, H₂O, BF₃

B. Covalent bonds: HF, H₂O, BF₃

C. Ionic bond: LiF

D. Hydrogen bonds: HF, H₂O

E. All are correct.

Explanation:

All are correct except A. Polar bonds: HF, LiF, and H₂O, but non-polar bond: BF₃

13 / 20

Which of the following bonds has the highest polarity?

A. C–F

B. C–N

C. C–O

D. C–C

E. F–F

Explanation:

The bigger difference in electronegativity between two atoms, the higher polarity. The C-F bond has the biggest difference of electronegativity among them.

14 / 20

Choose an INCORRECT statement about the two bonds between H-F and H-Cl.

A. H-F bond has bigger difference of electronegativity than H-Cl.

B. H-F bond has higher polarity than H-Cl.

C. H-F bond has a higher boiling point than H-Cl.

D. H-F bond has a higher melting point than H-Cl.

E. All are correct.

Explanation:

All are correct statements. H-F has a hydrogen bond, so this bond has a higher melting and boiling point than H-Cl even though H-Cl has a higher molecular weight than H-F.

15 / 20

Which of the following is the most important factor in determining the polar covalent bonded or non-polar covalent bonded molecules?

A. Electronegativity

B. Valence electrons

C. Electro affinity

D. Ionization energy

E. Molecular weight

Explantion:

The polarity of molecules is decided by the difference in electronegativity between two atoms.

16 / 20

Which of the following substances is the most easily soluble in the water at the same temperature and pressure?

A. BF₃

B. NH₃

C. CH₄

D. CO₂

E. BeF₂

Explanation:

NH₃ and H₂O are polar molecular compounds. The polar molecules are easily soluble in polar solvent and the non-polar molecules are easily soluble in non-polar solvent. Therefore, NH₃ can easily solve in H₂O.

17 / 20

Which of the following is a non-polar molecular compound?

A. CH₄

B. Cl₂

C. PH₃

D. CHCl₃

E. A and B

Explanation:

PH₃ and CHCl₃ are polar molecular compounds because the sum of the vector of polarities is not zero. In a non-polar molecular compound, the sum of the dipole moments is zero.

18 / 20

Which of the following is the correct statement?

A. To make a strong hydrogen bond, hydrogen must combine with atoms that have a strong electronegativity and smaller atomic radius.

B. London dispersion force is a stronger bond than dipole-dipole force when the molecules have a similar molecular weight.

C. Halogen and noble gases usually both have London dispersion and dipole-dipole forces.

D. The strength order of the boiling and melting point from lower to higher is HI < HBr < HCl.

E. Molecules that have covalent bonds have a higher polarity than molecules that have ionic bonds.

Explanation:

Dipole-dipole force is a stronger bond than London dispersion force when the molecules have a similar molecular weight. Halogen gases (F₂, Cl₂) and noble gases (Ne, Ar) have only London dispersion force because they are non-polar molecules. The strength order of the boiling and melting point from lower to higher is HCl < HBr < HI because the boiling and melting point of molecules usually depend on London dispersion force (molecular size or weight) rather than dipole-dipole force. Molecules that have ionic bonds have a higher polarity than the molecules that have covalent bonds.

19 / 20

Which of the following molecules has the highest boiling point?

A. CH₄

B. SiH₄

C. GeH₄

D. SnH₄

E. PbH₄

Explanation:

The molecular boiling point is affected by the molecular size between non-polar molecules (London dispersion force). A greater molecular size corresponds to a higher boiling point. Pb is the biggest element on the list.

20 / 20

Which of the following molecules have stable coordinate covalent bonds when two molecules are bonded together?

I. BF₃

II. H⁺

III. NH₃

IV. H₂O

A. I with II

B. I with III

C. II with IV

D. III with IV

E. B and C

Explanation:

Coordinate covalent bonds happen when one molecular having non-pair electrons accepts two lone-pair electrons. BF₃ and H⁺, which have non-pair electrons, accept two lone-pair electrons each from NH₃ and H₂O, and then become stable coordinate covalent molecules. This follows the octet rule.

Your score is

The average score is 39%

COMPOUND THEORY TEST 2

1 / 21

Which of the following apply to London dispersion forces?

I. The forces of the short-lived polarizability by electron motions in molecules.

II. The forces happening only between neighboring non-polar molecules.

III. Strength directly proportional to size of molecules.

IV. Lower melting and boiling point in larger sized molecules than in smaller sized molecules.

A. I only

B. I and II

C. I and III

D. I, II, and III

E. I, III, and IV

Explanation:

London dispersion forces happen by the short-lived polarizability from electron motions between two neighboring polar or non-polar molecules. Strength and melting and boiling points are directly proportional to the size of molecules.

2 / 21

Which of the following is the correct order for the predominant attractive forces between two molecules from lower to higher?

I. BF₃ – NH₄⁺

II. H₂O – H₂O

III. PH₃ – PH₃

A. I, II, III

B. II, I, III

C. I, III, II

D. III, I, II

E. III, II, I

Explanation:

The order of strength between molecules: London dispersion force < dipole-dipole force < hydrogen bond. The molecular force of I is London dispersion force, which is between non-polar molecules. II is a hydrogen bond., III is dipole-dipole force, which is between polar molecules.

3 / 21

All of the following molecules could have hydrogen bonds EXCEPT ____________________ .

A. NH₃

B. NF₃

C. H₂O

D. HF

E. None of the above

Explanation:

Hydrogen bond is the strong attractive force between molecules of N-H, O-H, and F-H.

4 / 21

Which of the following has the hydrogen bond between the molecules?

A. CH₃CH₂CH₃

B. CH₃CH₂F

C. N(CH₃)₃

D. CH₃Cl

E. CH₃CH₂OH

Explanation:

A, B, C, and D cannot have hydrogen bonds. Hydrogen bonded molecules have the interaction force between molecules of O-H, N-H, and F-H.

5 / 21

Choose the correct statement(s).

I. Atoms having the same number of valence electrons have similar chemical properties.

II. Carbon atoms in diamond crystal are bonded with 4 other carbons and have tetrahedral shape.

III. B, Al, and Kr do not follow the octet rule as a center atom in a molecule.

IV. Molecular structures with fewer resonances have greater stabilization.

A. I only

B. I and II

C. I, II, III

D. I, II, IV

E. All of the above

Explanation:

Molecular structures with more resonances have greater stabilization such as O₃, OCN^–, or NO₃^–.

6 / 21

Which of the following can NOT be a stable chemical formula that follows the octet rule?

W: 1 valance electron

X: 2 valance electrons

Y: 6 valence electrons

Z: 7 valence electrons

A. W₂Y

B. WZ

C. XY

D. Z₂

E. X₂Z

Explanation:

Stable molecules usually follow the octet rule. E cannot be a molecule formed by the octet rule.

7 / 21

Which of the following has the same lone pairs of electrons at the central atoms?

A. CH₂O and HO₂

B. H₂Se and PCl₃

C. NH₃ and IF₄⁺

D. BH₃ and ClF₃

E. BH₄^– and CH₃^–

Explanation:

NH₃ and IF₄⁺ have the 1 lone pair at their central atoms.

0 lone pair: CH₂O, BH₃, BH₄^–

1 lone pair: PCl₃, NH₃, IF₄⁺, CH₃^–

2 lone pairs: H₂O, H₂Se, ClF₃

8 / 21

Which compound follows the octet rule on the central atom?

A. BCl₃

B. BeBr₂

C. SbCl₅^2-

D. NH₄⁺

E. XeF₄

Explanation:

Atoms that could be the exception to the octet rule are Be, B, Al, Sb, Xe, and so forth (see Fig. 3 of this chapter).

9 / 21

Which of the following is the most stable resonance structure of N₂O?

Explanation:

B, D, and E do not follow the octet rule. Therefore, A and C could be the stable resonance structures. C is a more stable structure than A because of the negative charge on the oxygen, which has more electronegativity than nitrogen.

10 / 21

In the molecule PCl₃, the atom P has __________ lone pair(s) and __________ bond(s). Also, the total number of valence electrons in the molecule is __________.

A. 0, 2, 20

B. 1, 3, 20

C. 1, 2, 24

D. 1, 3, 26

E. 2, 3, 26

Explanation:

In the molecule PCl₃, there is 1 lone pair, 3 bonds, and 26 valence electrons.

11 / 21

According to VSEPR theory, what is the shape of XeOF₄ molecule?

A. Square planar

B. Linear

C. Trigonal planar

D. Square Planar

E. Square pyramidal

Explanation:

The shape of XeOF₄ is square pyramidal.

12 / 21

Which of the following has the most similar shape to AsCl₃by VSEPR theory?

A. NH₄⁺

B. PF₅

C. ClF₃

D. CCl₃^–

E. AlH₃

Explanation:

The shape of AsCl₃ is trigonal pyramidal.

NH₄⁺: Tetrahedral

PF₅: Trigonal bipyramidal

ClF₃: T-shaped

CCl₃^–: Trigonal pyramidal

AlH₃: Trigonal planar

Therefore, answer is D.

13 / 21

According to VSEPR theory, which of these molecules has a shape that is different from the others?

A. H₂O

B. SO₂

C. CS₂

D. Br₂O

E. H₂Te

Explanation:

All have a bent shape except CS₂. CS₂ has a linear shape.

14 / 21

Which of the following is an INCORRECT statement?

A. H-O-H bond angle in H₂O is 109.5°.

B. O-C-O bond angle in CO₂ is 180°.

C. F-B-F bond angle in BF₃ is 120°.

D. Cl-S-Cl bond angle in SCl₆ is 90°.

E. H-Si-H bond angle in SiH₄ is 109.5°.

Explanation:

H-O-H bond angle in H₂O is less than 109.5° because the electrons in two lone pairs repel each other.

15 / 21

Which of the following molecules has sp³ hybridization on the central atom?

A. ClF₃

B. KrF₂

C. PCl₃

D. BeCl₂

E. AlCl₃

Solution:

ClF₃: 3 bonds and 2 lone pairs (3+2) = sp³d (1+3+1)

KrF₂: 2 bonds and 3 lone pairs (2+3) = sp³d (1+3+1)

PCl₃: 3 bonds and 1 lone pair (3+1) = sp³ (1+3)

BeCl₂: 2 bonds and 0 lone pair (2+0) = sp (1+1)

AlCl₃: 3 bonds and 0 lone pair (3+0) = sp² (1+2)

16 / 21

A. 2, 7

B. 3, 3

C. 3, 6

D. 6, 3

E. 7, 2

Explanation:

17 / 21

A. –2

B. –1

C. 0

D. +1

E. +2

Explanation:

Formal charge

= Number of valence electrons – bonding number – number of non-binding electrons

= 5 – 2- 4

= -1

18 / 21

Which of the following is NOT related to paramagnetism?

A. Unpaired electrons

B. Positive susceptibility

C. Weaker than ferromagnetism

D. Short terms of magnets

E. Fe, Co, and Ni

Explanation:

Paramagnetism is the positive attractive force to magnetic field by unpaired electrons. This magnetism is weak and short term. Li, Na, Mg, Al, Ca, and O₂ are examples of paramagnetism. Fe, Co, and Ni are examples of ferromagnetism.

19 / 21

Which of the following is an example of paramagnetism?

A. O₂

B. F₂

C. Cu

D. Ag

E. Co

Explanation:

Paramagnetism: Li, Na, Mg, Al, Ca, O₂

Ferromagnetism: Fe, Co, Ni

Diamagnetism: Cu, Ag, Au, N₂, F₂

20 / 21

How many atoms are in a body-centered cubic unit cell?

A. 1

B. 2

C. 3

D. 4

E. 5

Explanation:

A body-centered cubic unit cell, which is one centered atom with 1/8 of each corner atom, has total two atoms.

21 / 21

Two crystal lattice structures have one atom and four atoms per unit cell. These structures are called _______________ and _______________.

A. Simple cubic, face-centered cubic

B. Body-centered cubic, face-centered cubic

C. Face-centered cubic, simple cubic

D. Body-centered cubic, simple cubic

E. Simple cubic, body-centered cubic

Explanation:

Simple cubic: 1 atom

Body-centered cubic: 2 atoms

Face-centered cubic: 4 atoms

Your score is

The average score is 30%

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