General Chemistry Exam 1 Review
Questions And Answers | Latest Update |
2024/2025 | 100% Pass
What is the primary difference between an ionic bond and a covalent bond in terms of electron
distribution?
✔✔ In an ionic bond, electrons are transferred from one atom to another, resulting in the
formation of ions, whereas in a covalent bond, electrons are shared between atoms.
How can you determine the empirical formula of a compound given its percent composition?
✔✔ The empirical formula can be determined by converting the percent composition to moles
for each element, finding the simplest whole number ratio among the elements, and using this
ratio to write the empirical formula.
What is the significance of Avogadro's number in chemistry?
✔✔ Avogadro's number defines the number of atoms or molecules in one mole of a substance,
which is approximately \(6.022 \times 10^{23}\).
How do you calculate the density of a substance, and what units are typically used?
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,✔✔ Density is calculated by dividing the mass of the substance by its volume, and it is typically
expressed in units such as grams per cubic centimeter (g/cm³) or kilograms per liter (kg/L).
What is the difference between a physical change and a chemical change?
✔✔ A physical change alters the state or appearance of a substance without changing its
chemical composition, whereas a chemical change results in the formation of new substances
with different chemical properties.
How is the molecular weight of a compound determined from its chemical formula?
✔✔ The molecular weight is calculated by summing the atomic weights of all the atoms in the
chemical formula of the compound.
What factors can influence the rate of a chemical reaction?
✔✔ Factors that can influence the rate of a chemical reaction include temperature, concentration
of reactants, surface area of reactants, and the presence of a catalyst.
What is the concept of conservation of mass in a chemical reaction?
✔✔ The conservation of mass states that in a chemical reaction, the total mass of reactants
equals the total mass of products, meaning mass is neither created nor destroyed.
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, How do you determine the number of significant figures in a measured quantity?
✔✔ The number of significant figures is determined by identifying all the non-zero digits, any
zeros between significant digits, and trailing zeros in the decimal portion of the number.
What is the role of a stoichiometric coefficient in a balanced chemical equation?
✔✔ Stoichiometric coefficients indicate the relative amounts of reactants and products involved
in a chemical reaction, ensuring that the law of conservation of mass is upheld.
How do you identify the oxidation states of elements in a compound?
✔✔ Oxidation states are identified based on a set of rules, such as the oxidation state of an
element in its elemental form is zero, the sum of oxidation states in a neutral compound equals
zero, and in compounds, more electronegative elements are assigned negative oxidation states.
What is the significance of the mole concept in stoichiometry?
✔✔ The mole concept allows chemists to relate the quantities of reactants and products in a
chemical reaction to a common unit, facilitating the calculation of amounts involved in reactions
based on molecular or atomic scale.
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Questions And Answers | Latest Update |
2024/2025 | 100% Pass
What is the primary difference between an ionic bond and a covalent bond in terms of electron
distribution?
✔✔ In an ionic bond, electrons are transferred from one atom to another, resulting in the
formation of ions, whereas in a covalent bond, electrons are shared between atoms.
How can you determine the empirical formula of a compound given its percent composition?
✔✔ The empirical formula can be determined by converting the percent composition to moles
for each element, finding the simplest whole number ratio among the elements, and using this
ratio to write the empirical formula.
What is the significance of Avogadro's number in chemistry?
✔✔ Avogadro's number defines the number of atoms or molecules in one mole of a substance,
which is approximately \(6.022 \times 10^{23}\).
How do you calculate the density of a substance, and what units are typically used?
1
,✔✔ Density is calculated by dividing the mass of the substance by its volume, and it is typically
expressed in units such as grams per cubic centimeter (g/cm³) or kilograms per liter (kg/L).
What is the difference between a physical change and a chemical change?
✔✔ A physical change alters the state or appearance of a substance without changing its
chemical composition, whereas a chemical change results in the formation of new substances
with different chemical properties.
How is the molecular weight of a compound determined from its chemical formula?
✔✔ The molecular weight is calculated by summing the atomic weights of all the atoms in the
chemical formula of the compound.
What factors can influence the rate of a chemical reaction?
✔✔ Factors that can influence the rate of a chemical reaction include temperature, concentration
of reactants, surface area of reactants, and the presence of a catalyst.
What is the concept of conservation of mass in a chemical reaction?
✔✔ The conservation of mass states that in a chemical reaction, the total mass of reactants
equals the total mass of products, meaning mass is neither created nor destroyed.
2
, How do you determine the number of significant figures in a measured quantity?
✔✔ The number of significant figures is determined by identifying all the non-zero digits, any
zeros between significant digits, and trailing zeros in the decimal portion of the number.
What is the role of a stoichiometric coefficient in a balanced chemical equation?
✔✔ Stoichiometric coefficients indicate the relative amounts of reactants and products involved
in a chemical reaction, ensuring that the law of conservation of mass is upheld.
How do you identify the oxidation states of elements in a compound?
✔✔ Oxidation states are identified based on a set of rules, such as the oxidation state of an
element in its elemental form is zero, the sum of oxidation states in a neutral compound equals
zero, and in compounds, more electronegative elements are assigned negative oxidation states.
What is the significance of the mole concept in stoichiometry?
✔✔ The mole concept allows chemists to relate the quantities of reactants and products in a
chemical reaction to a common unit, facilitating the calculation of amounts involved in reactions
based on molecular or atomic scale.
3
