CHM151 Rio Salado Midterm Questions
and Answers 100% Pass
What is the definition of an element in chemistry?
✔✔ An element is a substance that cannot be broken down into simpler substances by chemical
means and consists of only one type of atom.
How do you determine the number of protons in an atom?
✔✔ The number of protons in an atom is equal to the atomic number of the element.
What is the primary difference between an ionic bond and a covalent bond?
✔✔ An ionic bond is formed by the transfer of electrons from one atom to another, while a
covalent bond is formed by the sharing of electrons between atoms.
What is a chemical reaction?
✔✔ A chemical reaction is a process in which one or more substances are converted into
different substances with new chemical and physical properties.
What does the term "mole" refer to in chemistry?
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,✔✔ A mole is a unit that measures the amount of substance and is defined as \(6.022 \times
10^{23}\) particles, atoms, or molecules.
How is the molecular formula different from the empirical formula?
✔✔ The molecular formula shows the actual number of atoms of each element in a molecule,
while the empirical formula shows the simplest ratio of the elements in a compound.
What is the purpose of balancing a chemical equation?
✔✔ Balancing a chemical equation ensures that the number of atoms of each element is the same
on both sides of the equation, adhering to the law of conservation of mass.
What is the definition of a solution in chemistry?
✔✔ A solution is a homogeneous mixture composed of two or more substances where one
substance (the solute) is dissolved in another (the solvent).
What is the difference between an acid and a base according to the Bronsted-Lowry theory?
✔✔ According to the Bronsted-Lowry theory, an acid is a proton (H+) donor, and a base is a
proton acceptor.
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, What is meant by the term "oxidation state" of an element?
✔✔ The oxidation state of an element is the charge that an atom would have if all bonds to
atoms of different elements were 100% ionic.
How do you calculate the molar mass of a compound?
✔✔ To calculate the molar mass of a compound, sum the atomic masses of all the atoms in the
compound’s molecular formula.
What is a limiting reactant in a chemical reaction?
✔✔ The limiting reactant is the substance that is completely consumed first in a reaction and
determines the amount of product formed.
What is the difference between exothermic and endothermic reactions?
✔✔ An exothermic reaction releases heat to its surroundings, while an endothermic reaction
absorbs heat from its surroundings.
How do you find the concentration of a solution?
✔✔ The concentration of a solution can be found by dividing the amount of solute by the
volume of the solution, typically expressed in units such as molarity.
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and Answers 100% Pass
What is the definition of an element in chemistry?
✔✔ An element is a substance that cannot be broken down into simpler substances by chemical
means and consists of only one type of atom.
How do you determine the number of protons in an atom?
✔✔ The number of protons in an atom is equal to the atomic number of the element.
What is the primary difference between an ionic bond and a covalent bond?
✔✔ An ionic bond is formed by the transfer of electrons from one atom to another, while a
covalent bond is formed by the sharing of electrons between atoms.
What is a chemical reaction?
✔✔ A chemical reaction is a process in which one or more substances are converted into
different substances with new chemical and physical properties.
What does the term "mole" refer to in chemistry?
1
,✔✔ A mole is a unit that measures the amount of substance and is defined as \(6.022 \times
10^{23}\) particles, atoms, or molecules.
How is the molecular formula different from the empirical formula?
✔✔ The molecular formula shows the actual number of atoms of each element in a molecule,
while the empirical formula shows the simplest ratio of the elements in a compound.
What is the purpose of balancing a chemical equation?
✔✔ Balancing a chemical equation ensures that the number of atoms of each element is the same
on both sides of the equation, adhering to the law of conservation of mass.
What is the definition of a solution in chemistry?
✔✔ A solution is a homogeneous mixture composed of two or more substances where one
substance (the solute) is dissolved in another (the solvent).
What is the difference between an acid and a base according to the Bronsted-Lowry theory?
✔✔ According to the Bronsted-Lowry theory, an acid is a proton (H+) donor, and a base is a
proton acceptor.
2
, What is meant by the term "oxidation state" of an element?
✔✔ The oxidation state of an element is the charge that an atom would have if all bonds to
atoms of different elements were 100% ionic.
How do you calculate the molar mass of a compound?
✔✔ To calculate the molar mass of a compound, sum the atomic masses of all the atoms in the
compound’s molecular formula.
What is a limiting reactant in a chemical reaction?
✔✔ The limiting reactant is the substance that is completely consumed first in a reaction and
determines the amount of product formed.
What is the difference between exothermic and endothermic reactions?
✔✔ An exothermic reaction releases heat to its surroundings, while an endothermic reaction
absorbs heat from its surroundings.
How do you find the concentration of a solution?
✔✔ The concentration of a solution can be found by dividing the amount of solute by the
volume of the solution, typically expressed in units such as molarity.
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