Quiz 10

__________ is an example of an exothermic reaction. Burning wood Creating electricity Making ice Dissolving salt none of the above

Burning wood

Which of the following chemical reactions shows combustion? Fe+2 + H2O→ FeO + H2(g) HCl + NaOH → NaCl + H2O CH4 + 2O2 → CO2 + 2H2O Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O CaO + 2HCl → CaCl2 + H2O

CH4 + 2O2 → CO2 + 2H2O

__________ results in a sharing of many electrons between atoms. Metallic bonding Ionic bonding Covalent bonding all of the above none of the above

Metallic bonding

HCl reacting with __________ produces water plus salt. oxygen NaOH CaSO4 carbon none of the above

NaOH

__________ reacting with iron is an example of oxidation. Chlorine Sodium Oxygen Carbon none of the above

Oxygen

Which statement is true of liquid crystals? Could not be akin to the 'lipid bilayer' molecules in the primitive oceans. Liquid crystals become less structured in the presence of an electric field. Under the influence of an electric field, liquid crystals form a partially ordered structure of molecules. Polymers broken into individual parts reform as liquid crystals. Being a liquid, they have no order.

Under the influence of an electric field, liquid crystals form a partially ordered structure of molecules.

Most polymers are characterized as: permanently stable compounds. interesting to study, but having little value in our lives. a collection of small molecules combined into long chains. found in synthetic products, but not in nature. hard and brittle.

a collection of small molecules combined into long chains.

To see an everyday example of oxidation, you might observe: growing hair. glass breaking. a nail rusting. a thunderstorm. a light bulb shining.

a nail rusting.

Metals are held together because of: a sea of electrons. a sharing of electrons. an attraction between the polar molecules. a transfer of negative electrons. the lack of attraction between the inert atoms.

a sea of electrons.

Covalent solids are held together because of: a sea of electrons. a sharing of electrons. an attraction between the polar molecules. a transfer of negative electrons. the lack of attraction between the inert atoms.

a sharing of electrons.

Ionic solids are held together because of: a sea of electrons. a sharing of electrons. an attraction between the polar molecules. a transfer of negative charges: electrons the lack of attraction between the inert atoms.

a transfer of negative charges: electrons

Metallic bonds create materials with properties that make them: polar. able to change shape without breaking. brittle. good insulators. as hard as diamonds.

able to change shape without breaking.

Which of the following represents the most stable arrangement of electrons? atoms with completely filled valence shells elements that are positioned on the far right column of the periodic table of elements inert gases such as helium, neon and argon atoms with a total of 2, 10, 18 or 36 electrons all of the above

all of the above

Polar molecules are: never dipoles. always dipoles. sometimes dipoles. monopoles. none of the above

always dipoles.

An example of a metallic bond is: DNA. organic compounds. hydrogen gas. NaCl. an alloy.

an alloy.

The strongest type of bond is: ionic. metallic. covalent. van der Walls. none of the above.

covalent.

To save money, you bought a tougher cut of meat. Which of the following processes will you be using if you use a meat tenderizer? distillation condensation reaction precipitation dehydration synthesis depolymerization

depolymerization

Noble gases are called so because they: are considered more important than other elements. don't chemically interact with other elements. can chemically interact with many other elements. are very valuable. can exist in more forms than other elements.

don't chemically interact with other elements.

Exothermic and endothermic chemical reactions differ in that: energy is given off only in exothermic reactions. energy is given off only in endothermic reactions. the total energy in all involved electrons is the same before and after an exothermic reaction. the total energy in all involved electrons is the same before and after an endothermic reaction. only exothermic reactions can be observed in everyday life.

energy is given off only in exothermic reactions.

If a chemical bond forms spontaneously, then: energy will be released in the reaction. energy will be needed in the reaction. a change in state will always occur. a change in color will always occur. a plasma will always be formed.

energy will be released in the reaction.

Solids that do not have long-range order to the arrangement of their atoms are called: glass ionic solids. metallic solids. van der Waals solids. crystalline solids.

glass

A high octane rating in gasoline causes less engine 'knock' because: high octane gas is easier to distill than low octane. high octane is less complex hydrocarbons than low octane. high octane can withstand high compression in a cylinder without igniting. the isomer n-heptane is the primary component. high octane contains small amounts of isooctane.

high octane can withstand high compression in a cylinder without igniting.

Where would you not expect to find plasma? the Sun sealed in a magnetic bottle in an ice cube neon lights fluorescent light bulbs

in an ice cube

A piece of gravel by the side of road is most likely held together by: covalent bonds. ionic bonds. van der Waals forces. crystal lattice. hydrogen bonds.

ionic bonds.

Sodium chloride (NaCl) atoms form a crystal lattice that is held together by: hydrogen bonds. salt bonds. covalent bonds. ionic bonds. van der Waals bonds.

ionic bonds.

Which state of matter maintains a constant volume but not a fixed shape? gas plasma liquid crystal solid

liquid

The arrangement of the atoms in glass is: regular and repeating irregular in all places locally regular but overall not regular all of the above none of the above

locally regular but overall not regular

Which of the following is not characteristic of hydrogen bonds? separation of positively and negatively charged ions links of hydrogen to oxygen and other negative ions malleability and metallic bonds linking the two sides of the DNA double helix polar molecules

malleability and metallic bonds

Which makes the best electrical conductor? covalent bonds ionic bonds hydrogen bonds metallic bonds polymers

metallic bonds

No matter what element we consider, the electrons in the first shell are never: stripped off the atom. valence electrons. excited. all of the above none of the above

none of the above

An example of something that is not a polymer is: fur and cellulose. spider webs and plastic. nylon and cotton. meat. plasma and gas.

plasma and gas.

Chemical bonds occur when electrons are __________ atoms. stripped off expelled from rearranged between all of the above none of the above

rearranged between

Old oil can be __________ and used over again. burned broken down into elements refined and recycled all of the above none of the above

refined and recycled

If you drop a material that is held together by ionic bonds, one likely outcome is that it will: bend. shatter. flow across the floor. bounce. be dented.

shatter.

In which of the following places is more polymerization than depolymerization occurring? silk cocoon cow stomach compost heap art gallery birdbath

silk cocoon

The U.S. government once considered nylon as a (an): weapon of war. strategic material. form of currency. national uniform. none of the above

strategic material.

Chemical bonds are: the attraction among atoms resulting from the destruction of electrons. an unstable configuration among two or more elements. the redistribution of electrons between atoms, leading to a more stable configuration. sharing of protons in the lowest energy level. explained in laws of thermodynamics.

the redistribution of electrons between atoms, leading to a more stable configuration.

The electrons at the outer energy level of the atom are called: outer field electrons. the atomic number. valence electrons. van der Waals electrons. ionic electrons.

valence electrons.

The weakest type of bond is: ionic. metallic. covalent. van der Waals. none of the above.

van der Waals.

Which of the following common household products is an acid? detergent vinegar milk ammonia salt

vinegar