Questions and Answers
Which of the following are examples of a chemical change? (Select all that apply)
If an object has a density of 8.65 g/cm^3, what is its density in units of kg/m^3?
8.65 x 10^3 kg/m^3
Which of the following are examples of physical change? (Select all that apply)
Which of the following statements about energy is false?
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How many significant figures are in 3.408 x 10^4?
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What answer should be reported, with the correct number of significant figures, for the calculation (25.26 + 4.8)/0.700?
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Which of the following statements about the phases of matter is true?
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Which of the following are examples of intensive properties? (Select all that apply)
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Which of the following are examples of physical change? (Select all that apply)
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Choose the pure substance from the list below:
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Which of the following are examples of a chemical change? (Select all that apply)
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How many significant figures are in 1009.630 mL?
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A student performs an experiment to determine the density of a sugar solution. If the actual value for the density of the sugar solution is 2.73 g/mL, which statement best describes her results?
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A pure substance composed of 2 or more kinds of element atoms in a fixed, definite proportion is considered?
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An element can be described as?
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Which of the following represents a physical property?
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Which of the following represents a chemical property of hydrogen gas?
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Study Notes
Chemical Changes
- Leaves turning color in the fall is an example of a chemical change.
- Chemical changes involve alterations in the fundamental composition of a substance.
Density Conversions
- A density of 8.65 g/cm³ translates to 8.65 x 10³ kg/m³.
Physical Changes
- Brewing coffee, melting ice, and subliming dry ice are all examples of physical changes.
- Physical changes do not alter the composition but may change the state of matter.
Energy Properties
- Potential energy is incorrectly defined as motion-related; it actually refers to stored energy due to position.
- The total energy of a system remains constant, and energy can transform between types.
Significant Figures
- The number 3.408 x 10⁴ contains 4 significant figures.
- Correct significant figures must be adhered to in calculations, e.g., (25.26 + 4.8)/0.700 results in 43.0.
Phases of Matter
- In solids and liquids, atoms pack more closely compared to gases, which influences compressibility.
Intensive vs. Extensive Properties
- Density is an intensive property, meaning it does not depend on the amount of substance.
- Mass and volume are extensive properties that change with the quantity of material.
Identification of Physical Changes
- Dew forming on grass is a physical change, while cooking an egg is not.
Pure Substances
- Carbon monoxide is classified as a pure substance as it contains one kind of molecule.
More on Chemical Changes
- Building materials developing a green patina and burning matches are both chemical changes.
Precision and Accuracy in Measurements
- A set of measurements can be precise but inaccurate, as in the case of the density of a sugar solution.
Compounds and Elements
- A compound consists of two or more types of atoms in fixed ratios.
- An element is defined as a pure substance made up of identical atoms.
Physical Properties
- Mercury being a liquid at room temperature exemplifies a physical property.
- Sodium's reactivity and the flammability of butane are considered chemical properties.
Chemical Properties
- Hydrogen gas's explosive reaction with oxygen demonstrates its chemical property.
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Description
Test your knowledge with this Chemistry MC Quiz covering fundamental concepts from chapters 1-6 through 1-8. Each question is designed to assess your understanding of chemical changes, density, and more. Perfect for students looking to reinforce their chemistry skills.
