College PREP General Chemistry-
Chapter 1 & 2 Review | Latest Version |
2024/2025 | 100% Verified
What is the difference between a pure substance and a mixture, and how can they be separated?
✔✔ A pure substance has a consistent composition and properties throughout, consisting of only
one type of element or compound, while a mixture contains two or more substances that retain
their individual properties and can be separated by physical means like filtration or distillation.
How do you define the law of conservation of mass, and why is it fundamental in chemical
reactions?
✔✔ The law of conservation of mass states that mass is neither created nor destroyed in a
chemical reaction, meaning the total mass of reactants equals the total mass of products, which is
fundamental for balancing chemical equations.
What are the key differences between physical properties and chemical properties of matter?
✔✔ Physical properties can be observed or measured without changing the composition of the
substance, such as density or melting point, while chemical properties describe a substance's
ability to undergo a chemical change, such as flammability or reactivity.
1
, What is the concept of an element, and how does it differ from a compound?
✔✔ An element is a pure substance that consists of only one type of atom, while a compound is
a substance formed from two or more elements that are chemically bonded together in fixed
proportions.
How do you determine the number of significant figures in a measurement, and why are they
important in scientific calculations?
✔✔ Significant figures reflect the precision of a measurement by including all known digits plus
one estimated digit, and they are important in scientific calculations to ensure that the results are
not overrepresented in terms of accuracy.
What are the characteristics of a homogeneous mixture compared to a heterogeneous mixture?
✔✔ A homogeneous mixture has a uniform composition throughout, such as salt dissolved in
water, while a heterogeneous mixture has visibly different components or phases, such as oil and
water.
How does the concept of density relate to mass and volume, and how can it be used to identify a
substance?
✔✔ Density is defined as mass per unit volume and can be used to identify a substance because
each substance has a characteristic density under specific conditions.
2
Chapter 1 & 2 Review | Latest Version |
2024/2025 | 100% Verified
What is the difference between a pure substance and a mixture, and how can they be separated?
✔✔ A pure substance has a consistent composition and properties throughout, consisting of only
one type of element or compound, while a mixture contains two or more substances that retain
their individual properties and can be separated by physical means like filtration or distillation.
How do you define the law of conservation of mass, and why is it fundamental in chemical
reactions?
✔✔ The law of conservation of mass states that mass is neither created nor destroyed in a
chemical reaction, meaning the total mass of reactants equals the total mass of products, which is
fundamental for balancing chemical equations.
What are the key differences between physical properties and chemical properties of matter?
✔✔ Physical properties can be observed or measured without changing the composition of the
substance, such as density or melting point, while chemical properties describe a substance's
ability to undergo a chemical change, such as flammability or reactivity.
1
, What is the concept of an element, and how does it differ from a compound?
✔✔ An element is a pure substance that consists of only one type of atom, while a compound is
a substance formed from two or more elements that are chemically bonded together in fixed
proportions.
How do you determine the number of significant figures in a measurement, and why are they
important in scientific calculations?
✔✔ Significant figures reflect the precision of a measurement by including all known digits plus
one estimated digit, and they are important in scientific calculations to ensure that the results are
not overrepresented in terms of accuracy.
What are the characteristics of a homogeneous mixture compared to a heterogeneous mixture?
✔✔ A homogeneous mixture has a uniform composition throughout, such as salt dissolved in
water, while a heterogeneous mixture has visibly different components or phases, such as oil and
water.
How does the concept of density relate to mass and volume, and how can it be used to identify a
substance?
✔✔ Density is defined as mass per unit volume and can be used to identify a substance because
each substance has a characteristic density under specific conditions.
2
