Chapter 2: Chemistry Review
Which of the following statements correctly describe a properly balanced chemical equation? Select all that apply A- The number of molecules in the reactants should be the same as the number of molecules in the products B- The physical states of the reactants may be different that the physical states of the products C- The total number of atoms of each element must be the same in the reactants and the products D- The mass of the reactants is not necessarily the mass of the products
B and C
Ozone decomposes into oxygen and atomic oxygen. Which of the following statements correctly describe the balanced equation for this reaction? Select all that apply A- O2 is a product of the reaction B- There are 3 atoms of oxygen on the left side of the reaction and 3 atoms of oxygen on the product side of the reaction C- O3 is a product of the reaction D- A coefficient of one is needed on the reactant side
A and B
Define secondary pollution:
A secondary pollutant is a pollutant produced from one or more other pollutants
What is a catalyst?
A substance that increases the rate of a chemical reaction
Describe hydrocarbons
Are obtained from crude oil Gasoline and kerosene are mixtures of hydrocarbons
Which of the following options correctly describes the symbols used to write a balanced equation? Select all that apply A- The symbol (s) indicates that a substance is in a solution B- A pure liquid is indicated by the symbol (l) C- The symbol (g) indicates a substance in the gas phase D- The symbol (p) indicates a powdered substance
B and C
Balance the following chemical equation: C3H8 + O2 -> CO2 + H2O
C3H8 + 5O2 -> 3CO2 + 4H2O
What pollutants are generally produced by cars?
Carbon monoxide (CO) Nitrogen oxides Volatile Organic Compounds (VOC's)
Particulate matter with the designation PM10 includes particles with an average diameter of 10 ___ or less A- nm B- cm C- mm D- μm
D
Which of the following is the correct name of NO2? A- nitrogen oxide B- nitride dioxide C- mononitrogen dioxide D- nitrogen dioxide
D
Which of the following is a natural source of both ozone and nitrogen oxides? A- Earthquake B- Volcano eruption C- Wildfire D- Lightning
D- Lightning
In a combustion reaction, a hydrocarbon reacts with oxygen to produce carbon dioxide and water. Note that the oxygen found in the reactants ends up in both products. In order to balance the chemical equation in the most efficient manner, it is best to balance the oxygen atoms _____
Last; because in these cases it is best to balance the elements that appear in only one substance first
Which compound reacts with ozone, reducing the ozone concentrations along congested highways?
NO: because NO+O3=NO2+O2
Which species are involved in the conversion of NO to NO2 in the atmosphere?
O3 (ozone) VOC's OH (hydroxyl radical)
A molecule that always contains carbon and may contain hydrogen, oxygen and nitrogen is called an ____ compound
Organic
A chemical reaction is a process whereby substances called ____ are transformed into different substances called ___
Reactants, products
What are the sources and environmental effects of SO2 (sulfur dioxide)?
SO2 can react with water to produce acid rain SO2 can lead to the formation of aerosols
Describe aerosols
SO3 can combine with water to create sulfuric acid aerosols Aerosols are liquid and solid particles that remain suspended in the air Aerosols can contribute to pollution
What term is used to describe a situation where a resource in no particular groups responsibility but if it is destroyed or overused this has consequences for a large number of people?
Tragedy of the commons
Which two pollutants are responsible for the production of ozone in the trophosphere?
Volatile organic compounds (VOC's) Nitrogen dioxide
Describe the formation and control of pollutants produced by cars:
Volatile organic compounds are connected to the formation of nitrogen dioxide Catalytic converters have reduced the CO emissions from cars
Common name for H20
Water
penta-
five
A chemical equation is a statement using chemical ___ that expresses both the identities and the relative ___ of the reactants and products involved in a chemical or physical change
formula, amounts
Hydrocarbons are primarily used as ___
fuel
what does (g) in an equation stand for?
gas
What concentration of ozone is in our troposphere on sunny days?
higher levels of O3
A volatile substance readily undergoes a phase change from ___
liquid to gas
What concentration of ozone is in our troposphere on rainy and windy days?
lower levels of O3
Common name for CH4
methane
During a chemical reaction, the number of different substances may or may not change, but the total mass of the matter present ___
remains unchanged
hepta-
seven
hexa-
six
Atmospheric nitrogen reacts with atmospheric oxygen to form nitrogen monoxide. Which of the following is the correct balanced equation for this process? A- N2+O2 -> 2NO B- 2N2+2O2 -> 4NO C- N2+O2 -> NO D- N+O -> NO
A
Combustion is correctly described as ____ A- The process in which a substance burns in oxygen B- Any process that produces heat C- The combination of any substances with nitrogen D- Any chemical reaction involving oxygen
A
What are sources of particulate matter?
Burning coal Diesel engines Wildfires
True or False: Global greenhouse gas emissions can be thought of as an example of a tragedy of the commons
True Everyone is affected by everyone's emissions. This means that the air is the resource common to all and no one in particular is responsible for all of it
Combustion is an example of a type of chemical ____ where reactants are transformed into products
reaction
The common name for the compound H2O is ___ while the common name for the compound NH3 is ___
water and ammonia
Which of the following actions are permitted in balancing a chemical equation? A- Adding reactants or products B- Altering the formulas of the reactants or products C- Multiplying all coefficients by a common factor D- Adding coefficients to formulas of reactants and products
C and D
Balanced the unbalanced equation given and match each substance to the correct coefficient as indicated. Al+O2 -> Al2O3 A- Al 1. 2 B- O2 2. 3 C- Al2O3 3. 4
A and 3 B and 2 C and 1
What is the primary source of atmospheric sulfur dioxide (SO2)?
Coal-burning power plants
A species that passes easily from the liquid to the vapor phase is called a ____ substance
Combustible
Which of the following correctly describes how to name a compound containing 2 nonmetals? Select all that apply A- If only one atom of an element is present, the prefix mon- or mono- is always used B- A Greek numerical prefix is always used when more than one atom is present to indicate the number of atoms of each element in the compound C- The name of the first element remains unchanged, except for the addition of a prefix where appropriate D- The second element is named with its root and the suffix -ide
B, C and D
Match each air pollutant with its natural sources A- sulfur dioxide 1- includes dust and pollen B- Nitrogen oxide & ozone 2- produced during lightning strike C- Carbon monoxide 3- released by volcanos D- Particulate matter 4-may be produced by a wildfire
A and 3 B and 2 C and 4 D and 1
Which of the following statements correctly describe the information gained from a balanced chemical equation? Select all that apply A- Identities of the substances involved B- Temperature at which the reaction is carried out C- How fast a given reaction proceeds D- Relative quantities of substances involved E- Often the physical states of reactants and products
A, D and E
A chemical equation that is properly balanced obeys the law of ___
Conservation of Mass
what does (aq) in an equation stand for?
aqueous
Which of the following is a natural source of both ozone (O3) and nitrogen oxides (NOx)? A- Wildfire B- Lighting C- Earthquake D- Volcano eruption
A- wildfire
What products may be formed when a hydrocarbon undergoes combustion? Select all that apply A- CO B- CO2 C- CH4 D- O2 E- heat
A, B and E
Which of the following are considered air pollutants? A- Nitrogen B- Particulate Matter C- Ozone D- Nitrogen Dioxide E- Argon F- Carbon monoxide
B, C, D and F
Which of the following options describe particulate matter? Select all that apply A- Particulate matter is classified by composition B- The most dangerous particulate matter is visible as soot or smoke C- Some particulate matter can pass into the bloodstream and cause heart disease D- Dust is an example of particulate matter E- Particulate matter can originate from fires, car engines, or coal-burning plants.
C, D and E
Formula for the compound: dichlorine pentoxide
Cl2O5
The correct formula for the compound dichlorine pentoxide is Cl_O_
Cl2O5
True or false: In order to balance the reaction of hydrogen gas (H2) with oxygen gas (O2) to form liquid H20 a student adds a subscript of 2 to the oxygen in H2O. This is an acceptable method of balancing the above reaction
False
Even in very small concentrations ozone can affect ___ function in humans. Ozone also damages ___ which are essential to human life
Lungs; crops
What ailment is the primary hazard associated with exposure to particulate matter?
Melanoma Eczema and skin lesions
If a compound of nitrogen and hydrogen atoms in a respective one-to-three ratio, what is the correct chemical formula for this compound?
NH3
When balancing a combustion reaction, which element should be balanced last?
Oxygen, because it is the only element that appears in its elemental form in the equation, therefore it can be adjusted independently once C and H are balanced
True or false: After the completion of a chemical reaction the number of substances may change but the total mass of matter present remains constant.
True
Droplets that contain suspended solid and liquid particles are called ____
aerosols
Common name for NH3
ammonia
Organic compounds always contain the element ___
carbon
Volatile organic compounds are ____- containing compounds that pass easily into the ____ phase
carbon; gas
Greek numerical prefixes are used to indicate the number of atoms of a particular element present in a covalent compound. The prefix ____ indicates 10 atoms of the same element, while the prefix hexa- is used to indicate ___ atoms of the same element.
deca, 6
The chemical formula CCl4 indicates that there is/are _ carbon atom(s) for every _ chlorine atom(s)
1 and 4
Steps involved in ozone production:
1.) Nitrogen dioxide is exposed to sunlight 2.) Nitrogen monoxide and an oxygen atom are produced 3.) An oxygen atoms reacts with an oxygen molecule 4.) Ozone is produced
Which of the following statements correctly describe a properly balanced chemical equation? Select all that apply A- The physical states of the reactants may be different than the physical states of the products B- The mass of the reactants is not necessarily the same as the mass of the products C- The number of molecules in the reactants must be the same as the number of molecules in the products D- The total number of atoms of each element must be the same in the reactants and the products
A and D
Compounds that are made up of only hydrogen and carbon are called ____
hydrocarbons or organic
Hydrocarbons are compounds that contain only ___ and ___
hydrogen and carbon
what does (l) in an equation stand for?
liquid
A chemical equation must be balanced. This means that the same ___ and ___ of atoms must appear on both sides of the equation.
number and type
mono-
one
what does (s) in an equation stand for?
solid
What may increase the concentration of tropospheric ozone?
sunny day and stagnant air
di-
two
VOC's or ___ are a class of air pollutant that typically originates from ____
volatile organic compounds; cars
Balance the following chemical equation: SO2 + O2 -> SO3
2SO2 + O2 -> 2SO3
When naming a compound composed of 2 nonmetals, the number of atoms of each element is indicated by a Greek numerical ___
prefix
Describe the ozone exposure and its effects:
ozone reduces lung function ozone reacts with the rubber on car tires
Balance the following chemical equation: C4H10 + O2 -> CO2 + H20
2C4H10 + 13O2 -> 8CO2 + 10 H2O
Which of the following options correctly describe air pollutants? Select all that apply. Multiple select question. A- Particulate matter is an example of an air pollutant. B- Any substances other than nitrogen and oxygen are considered air pollutants. C- All air pollutants are gases. D- Some air pollutants are hazardous at levels well below 1 ppm. E- Sulfur dioxide is the only gaseous air pollutant that is odorless.
A and D
Which of the following options correctly describe how to name a compound containing two nonmetals? Select all that apply A- The second element is named with its root and the suffix -ide B- If only one atom of an element is present, the prefix mon- or mono- is always used C- A Greek numerical prefix is always used when more than one atom is present to indicate the number of atoms of each element in the compound D- The name of the first element remains unchanged, except for the addition of a prefix where appropriate.
A, C and D
Common name for O3
ozone
