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AC-HPAT CHEMISTRY QUESTIONS
WITH COMPLETE SOLUTIONS.
"Rust proofing - CORRECT ANSWER Rustproofing is the prevention or delay of rusting of iron and steel
objects, or the permanent protection against corrosion. Typically, the protection is achieved by a process of surface finishing or treatment. When the oil spray contacts the surface of your car it lifts off any amount of moisture that might be clinging to it. As thin as water itself, the oil can reach into every little seam and spot weld on your vehicle"
"cathodic protection - CORRECT ANSWER Cathodic protection (CP) is a technique used to control the
corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" to act as the anode."
"Galvination - CORRECT ANSWER Galvanization or galvanizing (also spelled galvanisation or galvanising)
is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of molten hot zinc."
"Molar Mass - CORRECT ANSWER - In chemistry, the molar mass of a chemical compound is defined as
the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles
- The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance (mol). The molar mass of a compound can be calculated by adding the standard atomic masses (in g/mol) of the constituent atoms."
"Molar concentration - CORRECT ANSWER Molar concentration (also called molarity, amount
concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution"
"Percent yield - CORRECT ANSWER Percent yield is the percent ratio of actual yield to the theoretical
yield. It is calculated to be the experimental yield divided by theoretical yield multiplied by 100%. It's possible for percent yield to be over 100%, which means more sample was recovered from a reaction than predicted"
"Ozone layer - CORRECT ANSWER Ozone Layer is a layer of the earth's upper atmosphere that is
characterized by high ozone content which blocks most of the sun's ultraviolet radiation from entering the lower atmosphere"
"Titration - CORRECT ANSWER Titration is the slow addition of one solution of a known concentration
(called a titrant) to a known volume of another solution of unknown concentration until the reaction reaches neutralization, which is often indicated by a color change."
"tropospheric ozone - CORRECT ANSWER Tropospheric ozone is a highly reactive oxidant that
significantly reduces crop productivity as well as the uptake of atmospheric carbon by vegetation. Its effects on plants include impeded growth and seed production, reduced functional leaf area and accelerated ageing."
"stratospheric ozone - CORRECT ANSWER Stratospheric ozone is a naturally occurring gas that filters the
sun's ultraviolet (UV) radiation. This is typically regarded as 'good' ozone since it reduces the harmful effects of ultraviolet (UV-B) radiation. A diminished ozone layer allows more radiation to reach the Earth's surface."
"Carbon Monoxide - CORRECT ANSWER Carbon monoxide is a relatively unreactive gas under ambient
air conditions and is not absorbed by building materials or ventilation system filters. Therefore, in the absence of indoor carbon monoxide sources, the indoor air concentration is the same as the concentration of ventilated or infiltrating outdoor air."
"Concentration - CORRECT ANSWER Concentration refers to the number of moles per volume are
contained within the solution. It also applies to how much of the acid or base is contained within the solution. An acid or base with a low number of ions has a low concentration and is therefore a weak acid or base."
"Concentration of an acid - CORRECT ANSWER The concentration of an acid is a measure of the amount
of available acid ions dissolved in a solvent. Concentration can be measured in moles, parts per million or percentage. The concentration is a ratio of the solute to solvent content of a solution."
"Precipitate - CORRECT ANSWER precipitate is an insoluble solid that emerges from a liquid solution. The
emergence of the insoluble solid from solution is called precipitation. Often the precipitate emerges as a suspension. Precipitates can form when two soluble salts react in solution to form one or more insoluble products."
"Marquis Test - CORRECT ANSWER The Marquis Test is commonly used for Ecstasy testing as MDMA
turns the precipitate purple black. Cobalt thiocyanate is used to test for cocaine. The Cobalt is mixed with the questionable substance, then drowned in hydrochloric acid, doused in chloroform, and shaken."
"What is the relation between an atomic number and a mass number? - CORRECT ANSWER Atomic
number is actually the number of protons in an atom while mass number is the number of nucleons i. e, number of protons plus the number of neutrons."
"Alcohol - CORRECT ANSWER alcohol is an organic compound that carries at least one hydroxyl
functional group (−OH) bound to a saturated carbon atom. ... An important class of alcohols, of which methanol and ethanol are the simplest members, includes all compounds for which the general formula is CnH2n+1OH."
"Aldehyde - CORRECT ANSWER aldehyde is a compound containing a functional group with the structure
−CHO, consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain."
"Ketone - CORRECT ANSWER a ketone is a functional group with the structure RC(=O)R', where R and R'
can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond)."
"carboxylic acid - CORRECT ANSWER carboxylic acid is an organic compound that contains a carboxyl
group (C(=O)OH). The general formula of a carboxylic acid is R-COOH, with R referring to the alkyl group. Carboxylic acids occur widely. Important examples include the amino acids and acetic acid."
"Ester - CORRECT ANSWER an ester is a chemical compound derived from an acid (organic or inorganic)
in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group. Usually, esters are derived from a carboxylic acid and an alcohol."
"Amines - CORRECT ANSWER Amines are formally derivatives of ammonia, wherein one or more
hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines)."
"Physical Properties of Oxygen: Liquid Oxygen: - CORRECT ANSWER Oxygen bubbles rise through pale-
blue liquid oxygen. Oxygen is more soluble in water than nitrogen is; water contains approximately one molecule of O2 for every two molecules of N2, compared to an atmospheric ratio of approximately one to four."
"Nitrogen - CORRECT ANSWER Nitrogen is a chemical element with symbol N and atomic number 7.
Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.09 percent of Earth's atmosphere by volume."
"Additional Reactions - CORRECT ANSWER Addition reactions occur when an atom is added to a
compound that has a double or triple bond. Unsaturated compounds are associated with addition reactions. ... Atoms can also be added to molecules in an addition reaction. However, atoms or molecules will never be eliminated or removed during this process."
"Substitution Reactions - CORRECT ANSWER Substitution reaction (also known as single displacement
reaction or single substitution reaction) is a chemical reaction during which one functional group in a
chemical compound is replaced by another functional group. Substitution reactions are of prime importance in organic chemistry."
"Combustion Reaction - CORRECT ANSWER A combustion reaction is a reaction in which a substance
reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve O2 as one reactant. The combustion of hydrogen gas produces water vapor. Notice that this reaction also qualifies as a combination reaction."
"Fermentation - CORRECT ANSWER Fermentation is where all alcohol is created, distillation is where the
alcohol is separated and removed. In order for fermentation to occur, two things are needed: a raw material in liquid form that contains sugar, followed by the addition of yeast."
"galvanic cell - CORRECT ANSWER a device in which chemical energy is changed to electrical energy ex.
battery"
"How does the redox reaction occur in the electroplating process? - CORRECT ANSWER Plating is an
oxidation-reduction reaction, where one material gives up electrons (gets oxidized) and the other material gains electrons (gets reduced). The anode is the electrode at which oxidation occurs, and the cathode is the electrode at which reduction occurs. Oxidation-reduction (redox) reactions are important because they are the principal sources of energy on this planet, both natural or biological and artificial. Oxidation of molecules by removal of hydrogen or combination with oxygen normally liberates large quantities of energy."
"Why do metal orthodontic braces not corrode? - CORRECT ANSWER Because orthodontic wires are
positioned close to the oral mucosa for lengthy periods, they should be resistant to corrosion and prevent the release of ions in the oral cavity, and should not cause allergic reactions. In other words, orthodontic wires must be biocompatible with oral tissues."
"Oxidation - CORRECT ANSWER Oxidation is any chemical reaction that involves the moving of electrons.
... When iron reacts with oxygen it forms a chemical called rust because it has been oxidized (the iron has lost some electrons) and the oxygen has been reduced (the oxygen has gained some electrons)."
"Anode vs Cathode - CORRECT ANSWER The anode of a device is the terminal where current flows in
from outside. The cathode of a device is the terminal where current flows out. ... By current we mean the positive conventional current. Since electrons are negatively charged, positive current flowing in is the same as electrons flowing out."
"Electrolyte - CORRECT ANSWER An electrolyte is a substance that produces an electrically conducting
solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent."
"Galvanic Corrosion - CORRECT ANSWER Galvanic corrosion occurs when two different metals are in
contact in a corrosive environment: one of the metals experiences an accelerated corrosion rate. The
"aspirin - CORRECT ANSWER Aspirin can be made by reacting salicylic acid with acetic acid in the
presence of an acid catalyst. The phenol group on the salicylic acid forms an ester with the carboxyl group on the acetic acid. However, this reaction is slow and has a relatively low yield"
"Ammonia - CORRECT ANSWER Ammonia is industrially prepared by the Haber process, a chemical
method that uses nitrogen gas and hydrogen gas to synthesize ammonia. One nitrogen gas molecule reacts with three hydrogen gas molecules over finely divided iron as a catalyst to produce two ammonia molecules."
"pH - CORRECT ANSWER pH is a measure of hydrogen ion concentration, a measure of the acidity or
alkalinity of a solution. The pH scale usually ranges from 0 to 14. Aqueous solutions at 25°C with a pH less than 7 are acidic, while those with a pH greater than 7 are basic or alkaline."
"What does ppm mean? - CORRECT ANSWER This is an abbreviation for "parts per million" and it also
can be expressed as milligrams per liter (mg/L). This measurement is the mass of a chemical or contaminate per unit volume of water. Seeing ppm or mg/L on a lab report means the same thing."
"what does ppb mean? - CORRECT ANSWER Parts per billion (ppb) is the number of units of mass of a
contaminant per 1000 million units of total mass. Also μg/L or micrograms per liter. Source: GreenFacts. More: ppb (or ppbm) is used to measure the concentration of a contaminant in soils and sediments."
"Neutralization - CORRECT ANSWER A neutralization reaction is when an acid and a base react to form
water and a salt and involves the combination of H+ ions and OH- ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7."
"greenhouse effect - CORRECT ANSWER warming that results when solar radiation is trapped by the
atmosphere"
"Chlorofluorocarbons - CORRECT ANSWER Chlorofluorocarbons (CFCs) are nontoxic, non-flammable
chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants."
"acid-base reactions - CORRECT ANSWER acid-base reactions are characterized by acids, which
dissociate in aqueous solution to form hydrogen ions (H+) and bases, which form hydroxide (OH−) ions. Acids are defined as a compound or element that releases hydrogen (H+) ions into the solution (mainly water)"
"Strong vs weak acids - CORRECT ANSWER Strong acids are fully ionised but weak acids are only partly
ionised in solution. At the same concentration, strong acids have a higher concentration of hydrogen ions than weak acids."
"Weak/Strong Base - CORRECT ANSWER A weak base is one that only partially dissociates to give ions in
solution. A strong base is one that fully dissociates to give ions in solution. ... Weak bases have pH 7.3 - 10, strong ones have pH 10 - 14. The weak bases have a lower equilibrium constant, while the strong bases have a higher equilibrium constant."
“Double-displacement reaction - CORRECT ANSWER A double displacement reaction, also known as a
double replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products"
"Energy Levels - CORRECT ANSWER Energy levels (also called electron shells) are fixed distances from
the nucleus of an atom where electrons may be found. As you go farther from the nucleus, electrons at higher energy levels have more energy. Electrons in the outermost energy level of an atom are called valence electrons"
"Isotopes - CORRECT ANSWER Isotopes refer to the nuclides of a certain element that have different
numbers of neutrons, or in other words, atomic nuclei that have the same number of protons but different numbers of neutrons. A radioisotope is an isotope that is unstable and therefore undergoes radioactive decay or will at some point."
"Precipitation reaction - CORRECT ANSWER A precipitation reaction refers to the formation of an
insoluble salt when two solutions containing soluble salts are combined. The insoluble salt that falls out of solution is known as the precipitate, hence the reaction's name. Precipitation reactions can help determine the presence of various ions in solution."
"Covalent bonds - CORRECT ANSWER Covalent bonds are chemical bonds between two non-metal
atoms. An example is water, where hydrogen (H) and oxygen (O) bond together to make (H2O). A full outer shell usually has eight electrons, or two in the case of hydrogen or helium. ... Covalent bonds are formed by atoms sharing valence electrons."
"Alkenes - CORRECT ANSWER Alkenes are a class of hydrocarbons (e.g, containing only carbon and
hydrogen) unsaturated compounds with at least one carbon-to-carbon double bond. Another term used to describe alkenes is olefins. Alkenes are more reactive than alkanes due to the presence of the double bond"
"Alkane - CORRECT ANSWER an alkane, or paraffin (a historical name that also has other meanings), is an
acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon-carbon bonds are single."
"Alkyne - CORRECT ANSWER An alkyne is a molecule that has a triple bond between two carbon atoms.
They have general formula CnH2n-2. They are also called acetylenes. The smallest alkyne is acetylene, also
