Chemistry Diagnostic Exam: Quiz! Trivia

1. Which statement describes a chemical change?

Alcohol evaporates.

Water vapor forms snowflakes.

Table salt (NaCl) is crushed into powder.

Glucose (C6H12O6) and oxygen produce CO2 and H2O.

Three of them are physical changes (either phase change or shape change). A chemical reaction indicates a chemical change.

Explanation

Three of them are physical changes (either phase change or shape change). A chemical reaction indicates a chemical change.

2. What is the IUPAC name for the compound ZnO?

Zinc oxide

Zinc oxalate

Zinc peroxide

Zinc hydroxide

For ionic compounds, the metal is listed according to the atomic name and the nonmetal's ending is changed to end in -ide. OXygen becomes OXide.

Explanation

For ionic compounds, the metal is listed according to the atomic name and the nonmetal's ending is changed to end in -ide. OXygen becomes OXide.

3. What is the number of electrons in a completely filled second shell of an atom?

32

2

18

8

The maximum number in the second orbital is 8...check out the electron configurations.

Explanation

The maximum number in the second orbital is 8...check out the electron configurations.

4. Which atom attains a stable valence electron configuration by bonding with another atom?

Neon

Radon

Hydrogen

Helium

Process of elimination. Three of these are noble gases. Hydrogen needs one more electron for its full valence.

Explanation

Process of elimination. Three of these are noble gases. Hydrogen needs one more electron for its full valence.

5. A mixture of sand and table salt can be separated by filtration because the substances in the mixture differ in

Solubility in water

Freezing point

Density at STP

Boiling point

Sand doesn't dissolve in water. Filtration separates solids from liquids that are not soluble.

Explanation

Sand doesn't dissolve in water. Filtration separates solids from liquids that are not soluble.

6. An ion that consists of 7 protons, 6 neutrons, and 10 electrons has a net charge of

4−

3−

3+

4+

7 protons (+7)
10 electrons (-10)

The difference is -3.

Explanation

7 protons (+7)
10 electrons (-10)

The difference is -3.

7. Which quantity is equal to 50 kilojoules?

0.05 J

5000 J

500 J

50 000 J

50 kJ is the same as 50 x 1000 kJ

Explanation

50 kJ is the same as 50 x 1000 kJ

8. In the wave-mechanical model of the atom, an orbital is the most probable location of

A proton

A positron

A neutron

An electron

ORBITAL = ELECTRON...I hope you didn't get this wrong.

Explanation

ORBITAL = ELECTRON...I hope you didn't get this wrong.

9. Which Lewis electron-dot diagram represents a molecule having a nonpolar covalent bond?

Nonpolar bond means there is no difference in electronegativity. Cl-Cl bonds have no difference, so there is no polarity in the bond.

Explanation

Nonpolar bond means there is no difference in electronegativity. Cl-Cl bonds have no difference, so there is no polarity in the bond.

10. What is the number of electrons in an atom that has 3 protons and 4 neutrons?

1

7

3

4

Protons equal electrons.

Explanation

Protons equal electrons.

11. Which particle has the least mass?

Alpha particle

Beta particle

Neutron

Proton

Check out Table O for the comparison. The top number is the mass number.

Explanation

Check out Table O for the comparison. The top number is the mass number.

12. Which element has the lowest electronegativity value?

F

Fr

Cl

Cr

Electronegativity is how strongly an element wants an electron. Fluorine has the highest and Fr (on the opposite corner of the Periodic Table) has the lowest value. Look in Table S.

Explanation

Electronegativity is how strongly an element wants an electron. Fluorine has the highest and Fr (on the opposite corner of the Periodic Table) has the lowest value. Look in Table S.

13. In a propanal molecule, an oxygen atom is bonded with a carbon atom. What is the total number of pairs of electrons shared between these atoms?

1

2

3

4

The -CO bond is a double bond, and four electrons total are shared (two pairs).

Explanation

The -CO bond is a double bond, and four electrons total are shared (two pairs).

14. When dissolved in water, an Arrhenius base yields

Hydrogen ions

Hydronium ions

Hydroxide ions

Oxide ions

Arrhenius bases yield ONLY hydroxide as the negative ions.

Explanation

Arrhenius bases yield ONLY hydroxide as the negative ions.

15. Which element is paired with an excited-state electron configuration for an atom of the element?

Ca: 2-8-8-2

Na: 2-8-2

K: 2-6-8-3

F: 2-8

K is the only one that has an incomplete inner shell.

Explanation

K is the only one that has an incomplete inner shell.

16. Given the balanced equation representing a nuclear reaction:

Which phrase identifies and describes this reaction?

Fission, mass converted to energy

Fission, energy converted to mass

Fusion, mass converted to energy

Fusion, energy converted to mass

FUSION because two elements become one. Some mass is converted to energy.

Explanation

FUSION because two elements become one. Some mass is converted to energy.

17. Which sample of CO2 has a definite shape and a definite volume?

CO2 (aq)

CO2 (g)

CO2 (l)

CO2 (s)

Solids have a definite shape and definite volume...Remember? It was the dry ice lab.

Explanation

Solids have a definite shape and definite volume...Remember? It was the dry ice lab.

18. At standard pressure, CH4 boils at 112 K and H2O boils at 373 K. What accounts for the higher boiling point of H2O at standard pressure?

Covalent bonding

Ionic bonding

Hydrogen bonding

Metallic bonding

Hydrogen bonding occurs when a polar molecule unevenly shares electrons with hydrogen atoms...the hydrogen atoms tend to have a positive charge and are attracted to the negatively charged atoms in the same molecule.

Explanation

Hydrogen bonding occurs when a polar molecule unevenly shares electrons with hydrogen atoms...the hydrogen atoms tend to have a positive charge and are attracted to the negatively charged atoms in the same molecule.

19. Some solid KNO3 remains at the bottom of a stoppered flask containing a saturated KNO3(aq) solution at 22°C. Which statement explains why the contents of the flask are at equilibrium?

The rate of dissolving is equal to the rate of crystallization.

The rate of dissolving is greater than the rate of crystallization.

The concentration of the solid is equal to the concentration of the solution.

The concentration of the solid is greater than the concentration of the solution.

As some particles dissolve, others come out of solution and crystallize.

Explanation

As some particles dissolve, others come out of solution and crystallize.

20. The elements in Group 2 are classified as

Metals

Metalloids

Nonmetals

Noble gases

Metals make up the majority of the elements. All elements to the left of the "staircase" are metals. Metals lose electrons, making POSITIVE ions.

Explanation

Metals make up the majority of the elements. All elements to the left of the "staircase" are metals. Metals lose electrons, making POSITIVE ions.

21. Systems in nature tend to undergo changes toward

Lower energy and lower entropy

Lower energy and higher entropy

Higher energy and lower entropy

Higher entropy and higher entropy

Lower energy (heat is the lowest form of energy) and higher entropy...entropy is randomness.

Explanation

Lower energy (heat is the lowest form of energy) and higher entropy...entropy is randomness.

22. Given the equation and potential energy diagram representing a reaction:

If each interval on the axis labeled "Potential Energy (kJ/mol)" represents 10. kJ/mol, what is the heat of reaction?

+60. kJ/mol

+20. kJ/mol

+30. kJ/mol

+40. kJ/mol

Activation energy is the force it takes to "ROLL THE BALL UP THE HILL."

Explanation

Activation energy is the force it takes to "ROLL THE BALL UP THE HILL."

23. Which statement describes the distribution of charge in an atom?

A neutral nucleus is surrounded by one or more negatively charged electrons.

A neutral nucleus is surrounded by one or more positively charged electrons.

A positively charged nucleus is surrounded by one or more negatively charged electrons.

A positively charged nucleus is surrounded by one or more positively charged electrons.

POSITIVELY charged nucleus (protons are positive and neutrons are neutral) surrounded by NEGATIVELY charged electrons.

Explanation

POSITIVELY charged nucleus (protons are positive and neutrons are neutral) surrounded by NEGATIVELY charged electrons.

24.

Mass number, only

Atomic number, only

Both mass number and atomic number

Neither mass number nor atomic number

The top number is the mass number (protons + neutrons) and the bottom number is the atomic number (protons)

Explanation

The top number is the mass number (protons + neutrons) and the bottom number is the atomic number (protons)

25. Functional groups are used to classify

Organic compounds

Inorganic compounds

Heterogeneous mixtures

Homogeneous mixtures

organic compounds involve functional groups...If you get confused, look at Table R.

Explanation

organic compounds involve functional groups...If you get confused, look at Table R.

26. What is the total number of valence electrons in a germanium atom in the ground state?

22

2

32

4

Look at the electron configuration. The Ge atom has the last number of 4 (valence electron).

Explanation

Look at the electron configuration. The Ge atom has the last number of 4 (valence electron).

27. Based on Reference Table J, which two reactants react spontaneously?

Mg(s) + ZnCl2(aq)

Cu(s) + FeSO4(aq)

Pb(s) + ZnCl2(aq)

Co(s) + NaCl(aq)

Magnesium is higher than Zinc. It will oxidize.

Explanation

Magnesium is higher than Zinc. It will oxidize.

28. The elements on the Periodic Table are arranged in order of increasing

Atomic mass

Atomic number

Molar mass

Oxidation number

The Periodic Table is arranged by atomic number, or number of protons. While it may seem that it is also arranged according to atomic mass, it is not the case. The atomic mass skips around a bit in the transition elements (the skinny section where Fe and Cu are located).

Explanation

The Periodic Table is arranged by atomic number, or number of protons. While it may seem that it is also arranged according to atomic mass, it is not the case. The atomic mass skips around a bit in the transition elements (the skinny section where Fe and Cu are located).

29. As a result of the gold foil experiment, it was concluded that an atom.

Contains protons, neutrons, and electrons

Contains a small, dense nucleus

Has positrons and orbitals

Is a hard, indivisible sphere

The gold foil experiment showed us that the atom contains a small, dense nucleus...it also showed us that the atom was mostly empty space.

Explanation

The gold foil experiment showed us that the atom contains a small, dense nucleus...it also showed us that the atom was mostly empty space.

30. Given the equation representing a reversible reaction:

According to one acid-base theory, the reactant that donates an H+ ion in the forward reaction is

NH3(g)

H2O(l)

NH4+(aq)

OH (aq)

The water got rid of a proton (H+) and gave it to ammonia (NH3) to form NH4+

Explanation

The water got rid of a proton (H+) and gave it to ammonia (NH3) to form NH4+

31. Which sample of matter is classified as a substance?

Air

Ammonia

Milk

Seawater

Three of these are mixtures (air is a mixture of gases, milk has water and proteins, and seawater has salt and water).

Ammonia is ONLY NH3.

Explanation

Three of these are mixtures (air is a mixture of gases, milk has water and proteins, and seawater has salt and water).

Ammonia is ONLY NH3.

32. What occurs in order to break the bond in a Cl2 molecule?

Energy is absorbed.

Energy is released.

The molecule creates energy.

The molecule destroys energy.

To break something requires force, so the energy is absorbed.

Explanation

To break something requires force, so the energy is absorbed.

33. Which statement describes the particles of an ideal gas according to the kinetic molecular theory?

The gas particles are arranged in a regular geometric pattern.

The gas particles are in random, constant, straight-line motion.

The gas particles are separated by very small distances, relative to their sizes.

The gas particles are strongly attracted to each other.

Ideal gases have NO ATTRACTION. They have a RANDOM, STRAIGHT-LINE MOTION. They also have GREAT DISTANCES between them.

Explanation

Ideal gases have NO ATTRACTION. They have a RANDOM, STRAIGHT-LINE MOTION. They also have GREAT DISTANCES between them.

34. Given the balanced equations representing two chemical reactions: Cl2 + 2NaBr → 2NaCl + Br2 2NaCl → 2Na + Cl2 Which types of chemical reactions are represented by these equations?

Single replacement and decomposition

Single replacement and double replacement

Synthesis and decomposition

Synthesis and double replacement

1st reaction: single replacement (element and compound switch partners)
2nd reaction: decomposition (one breaks down into two)

Explanation

1st reaction: single replacement (element and compound switch partners)
2nd reaction: decomposition (one breaks down into two)

35. At 25°C, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 kPa. Then the gas is compressed to a volume of 80. mL. What is the new pressure of the gas if the temperature is held at 25°C?

69 kPa

93 kPa

160 kPa

230 kPa

P1: 125 kPa
V1: 145 mL
T1: 298 K (25 + 273)

P2: unknown
V2: 80 mL
T2: 298 K

Explanation

P1: 125 kPa
V1: 145 mL
T1: 298 K (25 + 273)

P2: unknown
V2: 80 mL
T2: 298 K

36. An ionic bond can be formed when one or more electrons are

Equally shared by two atoms

Unequally shared by two atoms

Transferred from the nucleus of one atom to the nucleus of another atom

Transferred from the valence shell of one atom to the valence shell of another atom

Ionic bonds involve the transfer of electrons. Electrons are not found in the nucleus.

Explanation

Ionic bonds involve the transfer of electrons. Electrons are not found in the nucleus.

37. A 2400.-gram sample of an aqueous solution contains 0.012 gram of NH3. What is the concentration of NH3 in the solution, expressed as parts per million?

5.0 ppm

15 ppm

20. ppm

50. ppm

grams of solute: 0.012 g NH3
grams of solution: 2400

Explanation

grams of solute: 0.012 g NH3
grams of solution: 2400

38. A solution consists of 0.50 mole of CaCl2 dissolved in 100. grams of H2O at 25°C. Compared to the boiling point and freezing point of 100. grams of H2O at standard pressure, the solution at standard pressure has

A lower boiling point and a lower freezing point

A lower boiling point and a higher freezing point

A higher boiling point and a lower freezing point

A higher boiling point and a higher freezing point

The ions interfere with the formation of ice as well affect the boiling point. They lower freezing point and raise the boiling points.

Explanation

The ions interfere with the formation of ice as well affect the boiling point. They lower freezing point and raise the boiling points.

39. Which formula represents the product of the addition reaction between ethene and chlorine, Cl2?

The CH2ClCH3 (chloroethane) is the result of an organic substitution reaction. When you have an addition reaction, something is ADDED to what you already have.

Explanation

The CH2ClCH3 (chloroethane) is the result of an organic substitution reaction. When you have an addition reaction, something is ADDED to what you already have.

40. A sealed, rigid 1.0-liter cylinder contains He gas at STP. An identical sealed cylinder contains Ne gas at STP. These two cylinders contain the same number of

Atoms

Electrons

Ions

Protons

Process of elimination, but any two equally-sized containers have the same number of particles of gas present at the same temperature and pressure.

Explanation

Process of elimination, but any two equally-sized containers have the same number of particles of gas present at the same temperature and pressure.

41. Which class of compounds contains at least one element from Group 17 of the Periodic Table?

Aldehyde

Amine

Ester

Halide

Halides include FLUORINE, CHLORINE, and BROMINE.

Explanation

Halides include FLUORINE, CHLORINE, and BROMINE.

42. Which equation represents a change that results in an increase in disorder?

I2 (s) → I2 (g)

CO2 (g) → CO2 (s)

2Na (s) + Cl2 (g) → 2NaCl (s)

2H2 (g) + O2 (g) → 2H2O (l)

3 of go "down" a phase and only one goes "up" a phase. Gases show the most entropy (disorder).

Explanation

3 of go "down" a phase and only one goes "up" a phase. Gases show the most entropy (disorder).

43. When a voltaic cell operates, ions move through the

Anode

Cathode

Salt bridge

External circuit

Ions travel through the salt bridge. The electrons travel from the anode to the cathode through the wire.

Explanation

Ions travel through the salt bridge. The electrons travel from the anode to the cathode through the wire.

44. At which temperature is the vapor pressure of ethanol equal to 80. kPa?

48°C

73°C

80.°C

101°C

Table H:
On the Y axis, locate 80 kPa and follow it to the right until you reach the graph for ethanol. Look on the X axis to determine the temperature, 73.

Explanation

Table H:
On the Y axis, locate 80 kPa and follow it to the right until you reach the graph for ethanol. Look on the X axis to determine the temperature, 73.

45. Given the balanced ionic equation representing a reaction:

Which half-reaction represents the reduction that occurs?