AC-HPAT Chemistry Exam 2025 With
Correct Answers
double-displacement reaction - correct answersA double displacement reaction, also known as a double f f f f f f f f f f f f f
replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the
f f f f f f f f f f f f f f f f
positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new
f f f f f f f f f f f f f f f f f
compounds or products f f
Precipitate - correct answersprecipitate is an insoluble solid that emerges from a liquid solution. The
f f f f f f f f f f f f f f f
emergence of the insoluble solid from solution is called precipitation. Often the precipitate emerges as a
f f f f f f f f f f f f f f f f
suspension. Precipitates can form when two soluble salts react in solution to form one or more insoluble
f f f f f f f f f f f f f f f f f
products.
Energy Levels - correct answersEnergy levels (also called electron shells) are fixed distances from the nucleus
f f f f f f f f f f f f f f f f
of an atom where electrons may be found. As you go farther from the nucleus, electrons at higher energy levels
f f f f f f f f f f f f f f f f f f f f
have more energy. Electrons in the outermost energy level of an atom are called valence electrons
f f f f f f f f f f f f f f f
Marquis Test - correct answersThe Marquis Test is commonly used for Ecstasy testing as MDMA turns the
f f f f f f f f f f f f f f f f f
precipitate purple black. Cobalt thiocyanate is used to test for cocaine. The Cobalt is mixed with the
f f f f f f f f f f f f f f f f f
questionable substance, then drowned in hydrochloric acid, doused in chloroform, and shaken.
f f f f f f f f f f f
, What is the relation between an atomic number and a mass number? - correct answersAtomic number is
f f f f f f f f f f f f f f f f f
actually the number of protons in an atom while mass number is the number of nucleons i. e, number of
f f f f f f f f f f f f f f f f f f f f
protons plus the number of neutrons. f f f f f
Isotopes - correct answersIsotopes refer to the nuclides of a certain element that have different numbers of
f f f f f f f f f f f f f f f f f
neutrons, or in other words, atomic nuclei that have the same number of protons but different numbers of
f f f f f f f f f f f f f f f f f f
neutrons. A radioisotope is an isotope that is unstable and therefore undergoes radioactive decay or will at
f f f f f f f f f f f f f f f f f
some point. f
Chemical Synthesis - correct answersChemical synthesis, the construction of complex chemical compounds
f f f f f f f f f f f f
from simpler ones. It is the process by which many substances important to daily life are obtained. It is applied
f f f f f f f f f f f f f f f f f f f f
to all types of chemical compounds, but most syntheses are of organic molecules.
f f f f f f f f f f f f
Decomposition - correct answersA decomposition reaction is a type of chemical reaction in which a single f f f f f f f f f f f f f f f f
compound breaks down into two or more elements or new compounds. These reactions often involve an f f f f f f f f f f f f f f f f
energy source such as heat, light, or electricity that breaks apart the bonds of compounds
f f f f f f f f f f f f f f
single-displacement reaction - correct answersA single-displacement reaction, also known as a single- f f f f f f f f f f f
replacement reaction, is a type of chemical reaction where an element reacts with a compound and takes the f f f f f f f f f f f f f f f f f f
place of another element in that compound. This type of reaction is typically pictured like this: Here, A replaces
f f f f f f f f f f f f f f f f f f f
B in the compound BC
f f f f
Flame test - correct answersflame test is an analytical procedure used in chemistry to detect the presence of
f f f f f f f f f f f f f f f f f f
certain elements, primarily metal ions, based on each element's characteristic emission spectrum. The color
f f f f f f f f f f f f f f
of flames in general also depends on temperature; see flame color.
f f f f f f f f f f
Precipitation reaction - correct answersA precipitation reaction refers to the formation of an insoluble salt f f f f f f f f f f f f f f f
when two solutions containing soluble salts are combined. The insoluble salt that falls out of solution is known
f f f f f f f f f f f f f f f f f f
as the precipitate, hence the reaction's name. Precipitation reactions can help determine the presence of
f f f f f f f f f f f f f f f
various ions in solution. f f f
organic compounds - correct answersAn organic compound is a substance that is added to a product, like food,
f f f f f f f f f f f f f f f f f f
to improve some qualities such as taste, smell, colour and texture. These substances can be both positive and
f f f f f f f f f f f f f f f f f f
negative for human health. f f f
Correct Answers
double-displacement reaction - correct answersA double displacement reaction, also known as a double f f f f f f f f f f f f f
replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the
f f f f f f f f f f f f f f f f
positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new
f f f f f f f f f f f f f f f f f
compounds or products f f
Precipitate - correct answersprecipitate is an insoluble solid that emerges from a liquid solution. The
f f f f f f f f f f f f f f f
emergence of the insoluble solid from solution is called precipitation. Often the precipitate emerges as a
f f f f f f f f f f f f f f f f
suspension. Precipitates can form when two soluble salts react in solution to form one or more insoluble
f f f f f f f f f f f f f f f f f
products.
Energy Levels - correct answersEnergy levels (also called electron shells) are fixed distances from the nucleus
f f f f f f f f f f f f f f f f
of an atom where electrons may be found. As you go farther from the nucleus, electrons at higher energy levels
f f f f f f f f f f f f f f f f f f f f
have more energy. Electrons in the outermost energy level of an atom are called valence electrons
f f f f f f f f f f f f f f f
Marquis Test - correct answersThe Marquis Test is commonly used for Ecstasy testing as MDMA turns the
f f f f f f f f f f f f f f f f f
precipitate purple black. Cobalt thiocyanate is used to test for cocaine. The Cobalt is mixed with the
f f f f f f f f f f f f f f f f f
questionable substance, then drowned in hydrochloric acid, doused in chloroform, and shaken.
f f f f f f f f f f f
, What is the relation between an atomic number and a mass number? - correct answersAtomic number is
f f f f f f f f f f f f f f f f f
actually the number of protons in an atom while mass number is the number of nucleons i. e, number of
f f f f f f f f f f f f f f f f f f f f
protons plus the number of neutrons. f f f f f
Isotopes - correct answersIsotopes refer to the nuclides of a certain element that have different numbers of
f f f f f f f f f f f f f f f f f
neutrons, or in other words, atomic nuclei that have the same number of protons but different numbers of
f f f f f f f f f f f f f f f f f f
neutrons. A radioisotope is an isotope that is unstable and therefore undergoes radioactive decay or will at
f f f f f f f f f f f f f f f f f
some point. f
Chemical Synthesis - correct answersChemical synthesis, the construction of complex chemical compounds
f f f f f f f f f f f f
from simpler ones. It is the process by which many substances important to daily life are obtained. It is applied
f f f f f f f f f f f f f f f f f f f f
to all types of chemical compounds, but most syntheses are of organic molecules.
f f f f f f f f f f f f
Decomposition - correct answersA decomposition reaction is a type of chemical reaction in which a single f f f f f f f f f f f f f f f f
compound breaks down into two or more elements or new compounds. These reactions often involve an f f f f f f f f f f f f f f f f
energy source such as heat, light, or electricity that breaks apart the bonds of compounds
f f f f f f f f f f f f f f
single-displacement reaction - correct answersA single-displacement reaction, also known as a single- f f f f f f f f f f f
replacement reaction, is a type of chemical reaction where an element reacts with a compound and takes the f f f f f f f f f f f f f f f f f f
place of another element in that compound. This type of reaction is typically pictured like this: Here, A replaces
f f f f f f f f f f f f f f f f f f f
B in the compound BC
f f f f
Flame test - correct answersflame test is an analytical procedure used in chemistry to detect the presence of
f f f f f f f f f f f f f f f f f f
certain elements, primarily metal ions, based on each element's characteristic emission spectrum. The color
f f f f f f f f f f f f f f
of flames in general also depends on temperature; see flame color.
f f f f f f f f f f
Precipitation reaction - correct answersA precipitation reaction refers to the formation of an insoluble salt f f f f f f f f f f f f f f f
when two solutions containing soluble salts are combined. The insoluble salt that falls out of solution is known
f f f f f f f f f f f f f f f f f f
as the precipitate, hence the reaction's name. Precipitation reactions can help determine the presence of
f f f f f f f f f f f f f f f
various ions in solution. f f f
organic compounds - correct answersAn organic compound is a substance that is added to a product, like food,
f f f f f f f f f f f f f f f f f f
to improve some qualities such as taste, smell, colour and texture. These substances can be both positive and
f f f f f f f f f f f f f f f f f f
negative for human health. f f f
