CHEM JAN 2011 REGENTS

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

Atomic mass

Atomic number

First ionization energy

Selected oxidation state

ATOMIC # = PROTON...nobody get's between me and my PROTONS.

(also, nobody knows who I am without my protons)

Explanation

ATOMIC # = PROTON...nobody get's between me and my PROTONS.

(also, nobody knows who I am without my protons)

2. The two forms of oxygen, O2(g) and O3(g), have

Different molecular structures and identical properties

Different molecular structures and different properties

Identical molecular structures and identical properties

Identical molecular structures and different properties

O2 and O3 are different. O2 is oxygen and O3 is ozone. Talk about different...

Explanation

O2 and O3 are different. O2 is oxygen and O3 is ozone. Talk about different...

3. A molecular compound is formed when a chemical reaction occurs between atoms of

Chlorine and sodium

Chlorine and yttrium

Oxygen and hydrogen

Oxygen and magnesium

The key word is MOLECULAR. Molecular means COVALENT bonds, and 75% of those bonds were ionic (metal + nonmetal). Only ONE was correct. AND IT WAS WATER...

Explanation

The key word is MOLECULAR. Molecular means COVALENT bonds, and 75% of those bonds were ionic (metal + nonmetal). Only ONE was correct. AND IT WAS WATER...

4. Which sample of water contains particles having the highest average kinetic energy?

25 mL of water at 95°C

45 mL of water at 75°C

75 mL of water at 75°C

95 mL of water at 25°C

AVERAGE KINETIC ENERGY means TEMPERATURE...the highest temperature is the 95C.

Explanation

AVERAGE KINETIC ENERGY means TEMPERATURE...the highest temperature is the 95C.

5. An oxidation-reduction reaction involves the

Sharing of electrons

Sharing of protons

Transfer of electrons

Transfer of protons

Somebody loses electrons, and somebody gains electrons...I'm just happy that I lost nothing...YET.

Explanation

Somebody loses electrons, and somebody gains electrons...I'm just happy that I lost nothing...YET.

6. Which energy change occurs in an operating voltaic cell?

Chemical to electrical

Electrical to chemical

Chemical to nuclear

Nuclear to chemical

VOLTAIC CELLS involve salt bridges, Table J, and all that stuff...CHEMICAL energy gives rise to ELECTRICAL energy.

Explanation

VOLTAIC CELLS involve salt bridges, Table J, and all that stuff...CHEMICAL energy gives rise to ELECTRICAL energy.

7. Which electron configuration represents the electrons of an atom in an excited state?

2-1

2-7-4

2-8-7

2-4

If an inner shell is not complete and an outer shell has electrons, it is EXCITED.

Explanation

If an inner shell is not complete and an outer shell has electrons, it is EXCITED.

8. What is the total number of neutrons in an atom of O-18?

18

16

10

8

Neutrons are calculated by subtracting the atomic number (8) from the isotope number (18), which leaves 10

Explanation

Neutrons are calculated by subtracting the atomic number (8) from the isotope number (18), which leaves 10

9. Which element is malleable and a good conductor of electricity at STP?

Argon

Carbon

Iodine

Silver

Characteristics of METALS...NA (silver) is a metal.

Explanation

Characteristics of METALS...NA (silver) is a metal.

10. Which one do you like?

A proton

An electron

A positron

A neutron

Electrons are found in ORBITALS. The orbitals are not rings, but rather CLOUDS where you will PROBABLY find an electron.

Explanation

Electrons are found in ORBITALS. The orbitals are not rings, but rather CLOUDS where you will PROBABLY find an electron.

11. An atom of any element must contain

An equal number of protons and neutrons

An equal number of protons and electrons

More electrons than neutrons

More electrons than protons

An atom has equal protons and electrons. ISOTOPES deal with neutrons. IONS have different number of electrons (which gives ions their charges).

Explanation

An atom has equal protons and electrons. ISOTOPES deal with neutrons. IONS have different number of electrons (which gives ions their charges).

12. Which statement describes the general trends in electronegativity and metallic properties as the elements in Period 2 are considered in order of increasing atomic number?

Both electronegativity and metallic properties decrease.

Both electronegativity and metallic properties increase.

Electronegativity decreases and metallic properties increase.

Electronegativity increases and metallic properties decrease.

Electronegativity increases because the atoms get smaller...metallic properties decrease because we are moving RIGHT.

Explanation

Electronegativity increases because the atoms get smaller...metallic properties decrease because we are moving RIGHT.

13. Which balanced equation represents a single- replacement reaction?

Mg + 2AgNO3 → Mg(NO3)2 + 2Ag

2Mg+O2→2MgO

MgCO3 → MgO + CO2

MgCl2 + 2AgNO3 → 2AgCl + Mg(NO3)2

RED/OX reactions are also single-replacement reactions.

Explanation

RED/OX reactions are also single-replacement reactions.

14. The valence electrons of a germanium atom in the ground state are located in the

First shell

Second shell

Third shell

Fourth shell

2
8
18
4...VALENCE!!!

Explanation

2
8
18
4...VALENCE!!!

15. Which list of elements contains a metal, a metalloid, a nonmetal, and a noble gas?

Be, Si, Cl, Kr

C,N,Ne,Ar

K, Fe, B, F

Na,Zn,As,Sb

If you learned ANYTHING from me, it was the PERIODIC TABLE. If you don't know this by now, you won't learn it. EVER.

I WISH MR. SWERINGEN HAD A CHEM REVIEW CLASS...

Explanation

If you learned ANYTHING from me, it was the PERIODIC TABLE. If you don't know this by now, you won't learn it. EVER.

I WISH MR. SWERINGEN HAD A CHEM REVIEW CLASS...

16. The temperature of a sample of water changes from 10°C to 20°C when the sample absorbs 418 joules of heat. What is the mass of the sample?

1 g

10 g

100 g

1000 g

Do the math: 418 / 10 (degrees C) =

Explanation

Do the math: 418 / 10 (degrees C) =

17. The sum of the atomic masses of the atoms in one molecule of C3H6Br2 is called the

Formula mass

Isotopic mass

Percent abundance

Percent composition

It's called the GRAM FORMULA MASS, and it's calculated by adding up the masses of every atom in the composition...FOR EXAMPLE: water is H2O...2 HYDROGEN (= 2 x 1) and 1 OXYGEN (1 x 16)...18 is the formula mass of water.

Explanation

It's called the GRAM FORMULA MASS, and it's calculated by adding up the masses of every atom in the composition...FOR EXAMPLE: water is H2O...2 HYDROGEN (= 2 x 1) and 1 OXYGEN (1 x 16)...18 is the formula mass of water.

18. When an atom of lithium loses an electron, the atom becomes a

Negative ion with a radius smaller than the radius of the atom

Negative ion with a radius larger than the radius of the atom

Positive ion with a radius smaller than the radius of the atom

Positive ion with a radius larger than the radius of the atom

When a metal (in this case, a GROUP ONE METAL) loses an electron, it tends to lose not only an electron, but rather an entire orbital.

LITHIUM BEFORE: 2-1
LITHIUM AFTER: 2

When you lose an orbital, you lose a little bit of the radius...

Explanation

When a metal (in this case, a GROUP ONE METAL) loses an electron, it tends to lose not only an electron, but rather an entire orbital.

LITHIUM BEFORE: 2-1
LITHIUM AFTER: 2

When you lose an orbital, you lose a little bit of the radius...

19. Given the equation:

Which type of reaction is represented by this equation?

Combustion

Esterification

Polymerization

Substitution

POLYMER is a long chain of the same thing. THIS IS A PERFECT EXAMPLE.

Explanation

POLYMER is a long chain of the same thing. THIS IS A PERFECT EXAMPLE.

20. Which substance can not be broken down by chemical means?

Ammonia

Antimony

Methane

Water

One is in TABLE E, one is in a fart, and the other is water. ONLY ANTIMONY (Sb) is an element. YOU CANNOT BREAK DOWN ELEMENTS.

Explanation

One is in TABLE E, one is in a fart, and the other is water. ONLY ANTIMONY (Sb) is an element. YOU CANNOT BREAK DOWN ELEMENTS.

21. Which two physical properties allow a mixture to be separated by chromatography?

Hardness and boiling point

Density and specific heat capacity

Malleability and thermal conductivity

Solubility and molecular polarity

If something is SOLUBLE, it can travel up the paper (think Living Environment lab). If something is POLAR, it will stick to something else (again, THINK).

Explanation

If something is SOLUBLE, it can travel up the paper (think Living Environment lab). If something is POLAR, it will stick to something else (again, THINK).

22. The graph below represents the uniform heating of a sample of a substance starting as a solid below its melting point.

Which statement describes what happens to the energy of the particles of the sample during time interval DE?

Average kinetic energy increases, and potential energy remains the same.

Average kinetic energy decreases, and potential energy remains the same.

Average kinetic energy remains the same, and potential energy increases.

Average kinetic energy remains the same, and potential energy decreases.

No temperature change, only potential energy.

Explanation

No temperature change, only potential energy.

23. Which statement compares the masses of two subatomic particles?

The mass of an electron is greater than the mass of a proton.

The mass of an electron is greater than the mass of a neutron.

The mass of a proton is greater than the mass of an electron.

The mass of a proton is greater than the mass of a neutron.

Protons and neutrons are the same mass. Electrons have very little (almost no) mass.

If you have any doubt, look at the TABLE O and pay attention to the mass.

Explanation

Protons and neutrons are the same mass. Electrons have very little (almost no) mass.

If you have any doubt, look at the TABLE O and pay attention to the mass.

24. The solubility of KCl(s) in water depends on the

Pressure on the solution

Rate of stirring

Size of the KCl sample

Temperature of the water

TABLE G. Notice how the KCl line goes up?? That's because the solubility increases with temperature.

Explanation

TABLE G. Notice how the KCl line goes up?? That's because the solubility increases with temperature.

25. Under which conditions of temperature and pressure does carbon dioxide gas behave most like an ideal gas?

Low temperature and low pressure

Low temperature and high pressure

High temperature and low pressure

High temperature and high pressure

HIGH TEMPERATURE (particles moving fast) and LOW PRESSURE (particles are expanding) is when gases behave like an IDEAL GAS.

Explanation

HIGH TEMPERATURE (particles moving fast) and LOW PRESSURE (particles are expanding) is when gases behave like an IDEAL GAS.

26. Which process results in a chemical change?

Tearing tin foil

Melting an iron bar

Crushing an aluminum can

Burning magnesium ribbon

Nothing can be UN-DONE...except for the ribbon. Or, if you took a picture next to it.

Explanation

Nothing can be UN-DONE...except for the ribbon. Or, if you took a picture next to it.

27. For a chemical reaction, the heat of reaction is equal to the

Potential energy of the reactants, only

Potential energy of the products, only

Potential energy of the products plus the potential energy of the reactants

Potential energy of the products minus the potential energy of the reactants

Start MINUS finish. BTW, activation energy is how far one must roll the ball (or rock) up the hill.

Explanation

Start MINUS finish. BTW, activation energy is how far one must roll the ball (or rock) up the hill.

28. The table below gives information about four aqueous solutions at standard pressure.

Which list of solutions is arranged in order from highest boiling point to lowest boiling point?

A, B, D, C

A, C, B, D

C, D, B, A

D, B, C, A

molecular compounds have lower boiling points...C is the only molecular compound, so it should be at the END.

Explanation

molecular compounds have lower boiling points...C is the only molecular compound, so it should be at the END.

29. Which compound is an electrolyte?

Butene

Propane

Dimethyl ether

Methanoic acid

ALL of them are organic compounds...though 3 of them are not ARRHENIUS ACIDS...

Explanation

ALL of them are organic compounds...though 3 of them are not ARRHENIUS ACIDS...

30. According to the Arrhenius theory, a base reacts with an acid to produce

Ammonia and methane

Ammonia and a salt

Water and methane

Water and a salt

BY DEFINITION: a neutralization reaction involves an Arrhenius acid + an Arrhenius base, producing water and a salt.

Explanation

BY DEFINITION: a neutralization reaction involves an Arrhenius acid + an Arrhenius base, producing water and a salt.

31. What is one benefit associated with a nuclear fission reaction?

The products are not radioactive.

Stable isotopes are used as reactants.

There is no chance of biological exposure.

A large amount of energy is produced.

Nuclear reactions produce a GREAT DEAL of energy.

Explanation

Nuclear reactions produce a GREAT DEAL of energy.

32. Which radioisotope is used for diagnosing thyroid disorders?

U-238

Pb-206

I-131

Co-60

Thyroids need iodine...just memorize this fact.

Explanation

Thyroids need iodine...just memorize this fact.

33. Which radioisotope emits alpha particles?

Fe-53

Sr-90

Au-198

Pu-239

Table N.

Explanation

Table N.

34. What is the net charge of an ion that has 8 protons, 9 neutrons, and 10 electrons?

1+

2+

1-

2-

2 more electrons than protons...which means the charge is MINUS TWO.

Explanation

2 more electrons than protons...which means the charge is MINUS TWO.

35. Which element has chemical properties that are most similar to the chemical properties of sodium?

Beryllium

Calcium

Lithium

Magnesium

SAME GROUP = SAME PROPERTIES.

Explanation

SAME GROUP = SAME PROPERTIES.

36. Which statement matches a subatomic particle with its charge?

A neutron has a negative charge.

A proton has a negative charge.

A neutron has no charge.

A proton has no charge.

PROTONS +
ELECTRONS -
NEUTRONS 0

Explanation

PROTONS +
ELECTRONS -
NEUTRONS 0

37. Given the balanced equation representing a reaction: Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g) This reaction occurs more quickly when powdered iron is used instead of a single piece of iron of the same mass because the powdered iron

Acts as a better catalyst than the single piece of iron

Absorbs less energy than the single piece of iron

Has a greater surface area than the single piece of iron

Is more metallic than the single piece of iron

POWDERED means more reactions.

Explanation

POWDERED means more reactions.

38. What is the total number of electron pairs shared between the two atoms in an O2 molecule?

1

2

6

4

2 THINGS YOU SHOULD HAVE KNOWN:

1. O2 is a double bond.
2. Each bond is 2 electrons (4 total)

Explanation

2 THINGS YOU SHOULD HAVE KNOWN:

1. O2 is a double bond.
2. Each bond is 2 electrons (4 total)

39. Given the balanced equation representing a reaction: 2NaCl → 2Na + Cl2 To break the bonds in NaCl, the reactant must

Absorb energy

Create energy

Destroy energy

Release energy

It takes money to make money, so I guess it should take energy to make energy.

(BAD ANALOGY)

breaking bonds takes energy...as does reading all the words that i've put out for you...

Explanation

It takes money to make money, so I guess it should take energy to make energy.

(BAD ANALOGY)

breaking bonds takes energy...as does reading all the words that i've put out for you...

40. The bright-line spectrum of sodium is produced when energy is

Absorbed as electrons move from higher to lower electron shells

Absorbed as electrons move from lower to higher electron shells

Released as electrons move from higher to lower electron shells

Released as electrons move from lower to higher electron shells

Bright-line goes from HIGHER to LOWER orbitals...as you go in, the energy decreases.

Explanation

Bright-line goes from HIGHER to LOWER orbitals...as you go in, the energy decreases.

41. Given the equation representing a system at equilibrium:

At equilibrium, the concentration of

SO2(g) must equal the concentration of SO3(g)

SO2(g) must be constant

O2(g) must equal the concentration of SO2(g)

O2(g) must be decreasing

FORWARD must equal REVERSE.

Explanation

FORWARD must equal REVERSE.

42. What is the total number of years that must pass before only 25.00 grams of an original 100.0-gram sample of C-14 remains unchanged?

2865 y

5730 y

11 460 y

17 190 y

2 HALF LIVES...which means there is 2 x 5730 years that have passed.

Explanation

2 HALF LIVES...which means there is 2 x 5730 years that have passed.

43. Which balanced equation represents a fusion reaction?

FUSION is when two become one.

Explanation

FUSION is when two become one.

44. If an element, X, can form an oxide that has the formula X2O3, then element X would most likely be located on the Periodic Table in the same group as

Ba

Cd

In

Na

Oxygen has an oxidation state of -2, while In has an oxidation state of +3...switch the numbers.

Explanation

Oxygen has an oxidation state of -2, while In has an oxidation state of +3...switch the numbers.

45. What is the total mass of KNO3 that must be dissolved in 50. grams of H2O at 60.°C to make a saturated solution?

32 g

53 g

64 g

106 g

TRICK QUESTION: The KNO3 is dissolved in 50 g water...divide the assumed answer by TWO.

Explanation

TRICK QUESTION: The KNO3 is dissolved in 50 g water...divide the assumed answer by TWO.

46. Given the reaction at 101.3 kilopascals and 298 K: hydrogen gas + iodine gas → hydrogen iodide gas This reaction is classified as

Endothermic, because heat is absorbed

Endothermic, because heat is released

Exothermic, because heat is absorbed

Exothermic, because heat is released

Consult TABLE I...this reaction is ENDOTHERMIC...

Explanation

Consult TABLE I...this reaction is ENDOTHERMIC...

47. Which molecule has a nonpolar covalent bond?

The only NONPOLAR bond is one that is bonded to itself.

Explanation

The only NONPOLAR bond is one that is bonded to itself.

48. Given the equation representing a reaction at equilibrium:

What occurs when the concentration of H2(g) is increased?

The equilibrium shifts to the left, and the concentration of N2(g) decreases.

The equilibrium shifts to the left, and the concentration of N2(g) increases.

The equilibrium shifts to the right, and the concentration of N2(g) decreases.

The equilibrium shifts to the right, and the concentration of N2(g) increases.

Le Chatelier's principle...If you go to the right, the reactants (N2 and H2) will decrease. The reaction always goes away from the thing that was increased...and towards the thing that was decreased.

Explanation

Le Chatelier's principle...If you go to the right, the reactants (N2 and H2) will decrease. The reaction always goes away from the thing that was increased...and towards the thing that was decreased.

49. The two isomers of butane have different

Formula masses

Empirical formulas

Molecular formulas

Structural formulas

ISOMER means different neutrons...NEUTRONS mean a different mass...AHEM.

Explanation

ISOMER means different neutrons...NEUTRONS mean a different mass...AHEM.

Chem Jan 2011 Regents