SPRING BREAK CHEM HW

1. 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 positive
electrons negative
neutrons no charge

Explanation

protons positive
electrons negative
neutrons no charge

2. 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

gram formula mass is the total of the quantities of each element along with their masses.

Explanation

gram formula mass is the total of the quantities of each element along with their masses.

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

First shell

Second shell

Third shell

Fourth shell

electron configuration is 2-8-18-4, meaning four electron shells.

Explanation

electron configuration is 2-8-18-4, meaning four electron shells.

4. An orbital is a region of space where there is a high probability of finding

Proton

Positron

Neutron

Electron

orbitals are the "rings" around the nucleus where an electron is likely to be found.

Explanation

orbitals are the "rings" around the nucleus where an electron is likely to be found.

5. 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

protons (+) and electrons (--) must be equal in an ATOM. If there is a charge, then the ATOM becomes an ION.

Explanation

protons (+) and electrons (--) must be equal in an ATOM. If there is a charge, then the ATOM becomes an ION.

6. 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 an ion loses an electron, the resulting ion is POSITIVE. Since the lithium atom lost its valence shell, the radius decreased.

Explanation

When an ion loses an electron, the resulting ion is POSITIVE. Since the lithium atom lost its valence shell, the radius decreased.

7. 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

metals = left side of periodic table
metalloids = along the staircase (except for Al)
nonmetals = upper right of periodic table
noble gas = group 18

Explanation

metals = left side of periodic table
metalloids = along the staircase (except for Al)
nonmetals = upper right of periodic table
noble gas = group 18

8. 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 the EXACT same thing as temperature.

Explanation

average kinetic energy means the EXACT same thing as temperature.

9. An oxidation-reduction reaction involves the

Sharing of electrons

Sharing of protons

Transfer of electrons

Transfer of protons

oxidation reactions lose electrons and reduction reactions gain electrons...the electrons are transferring.

Explanation

oxidation reactions lose electrons and reduction reactions gain electrons...the electrons are transferring.

10. Which process results in a chemical change?

Tearing tin foil

Melting an iron bar

Crushing an aluminum can`

Burning magnesium ribbon

burning magnesium ribbon involves changing the chemical content of the ribbon. The other three involve shifting the particles around slightly, not changing the composition.

Explanation

burning magnesium ribbon involves changing the chemical content of the ribbon. The other three involve shifting the particles around slightly, not changing the composition.

11. Given the equation representing a system at equilibrium: 2SO2(g) + O2(g) <--> 2SO3(g) 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

The forward reaction must equal the reverse reaction. When one substance moves forward in the reaction, another substance must move in the reverse direction, meaning all components are constant.

Explanation

The forward reaction must equal the reverse reaction. When one substance moves forward in the reaction, another substance must move in the reverse direction, meaning all components are constant.

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

Chemical to electrical

Electrical to chemical

Chemical to nuclear

Nuclear to chemical

As long as the solid is higher (on Table J) than the aqueous substance, the reaction will be spontaneous. The chemical difference causes the movement of electrons, meaning the energy changes from chemical energy in the solutions to electrical energy in the wires.

Explanation

As long as the solid is higher (on Table J) than the aqueous substance, the reaction will be spontaneous. The chemical difference causes the movement of electrons, meaning the energy changes from chemical energy in the solutions to electrical energy in the wires.

13. 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

think about the chromatography experiment from living environment: the pigments must be soluble in the solvent then their polarities enable them to stick to the surface.

Explanation

think about the chromatography experiment from living environment: the pigments must be soluble in the solvent then their polarities enable them to stick to the surface.

14. 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

MOLECULAR compound equals COVALENT bonds.

bonds between nonmetals (H and O) are covalent.
All other bonds involve metals and nonmetals (IONIC bonds).

Explanation

MOLECULAR compound equals COVALENT bonds.

bonds between nonmetals (H and O) are covalent.
All other bonds involve metals and nonmetals (IONIC bonds).

15. 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 have nearly equal masses.
electrons weigh 2000 times LESS than protons and neutrons.

Explanation

protons and neutrons have nearly equal masses.
electrons weigh 2000 times LESS than protons and neutrons.

16. 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

heat of reaction is a DIFFERENCE, indicating that subtraction is the math used.

Explanation

heat of reaction is a DIFFERENCE, indicating that subtraction is the math used.

17. 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

Heating the water will enable more KCl to dissolve. Check Reference Table G for further assistance.

Explanation

Heating the water will enable more KCl to dissolve. Check Reference Table G for further assistance.

18. 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

To break a bond, reactants must absorb energy. The energy is required to break any attractions between atoms in a compound.

Explanation

To break a bond, reactants must absorb energy. The energy is required to break any attractions between atoms in a compound.

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

Atomic mass

Atomic number

First ionization energy

Selected oxidation state

From left to right, the atomic numbers increase.

Explanation

From left to right, the atomic numbers increase.

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

1

2

6

4

one bond = 2 electrons.

oxygen gas is a double-bonded molecule, which means 4 electrons.

Explanation

one bond = 2 electrons.

oxygen gas is a double-bonded molecule, which means 4 electrons.

21. The two isomers of butane have different

Formula masses

Empirical formulas

Molecular formulas

Structural formulas

Isomer means that the substances are arranged differently. Their structures are different.

Explanation

Isomer means that the substances are arranged differently. Their structures are different.

22. 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 because the particles are moving faster, able to separate.
LOW PRESSURE because not much is keeping the particles together, able to expand like an ideal gas.

Explanation

HIGH TEMPERATURE because the particles are moving faster, able to separate.
LOW PRESSURE because not much is keeping the particles together, able to expand like an ideal gas.