Quarterly Assessment 1-regents Chemistry
NYS Regent Curriculum, mp 1.
Questions and Answers
- 1.
WHich of the following can not be decomposed into simpler substances?
- A.
Elements
- B.
Compounds
- C.
Solutions
- D.
Mixtures
Correct Answer
A. ElementsExplanation
Elements cannot be decomposed into simpler substances because they are already the simplest form of matter. Elements are made up of only one type of atom and cannot be broken down into simpler substances by chemical means.Rate this question:
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- 2.
The particle diagram below represents a sample of matter. Which best describes the composition of the sample?
- A.
A single element
- B.
A mixture of elements
- C.
A single compound
- D.
A mixture of compounds
Correct Answer
B. A mixture of elementsExplanation
The particle diagram represents a sample of matter that consists of different types of particles. Since there are multiple elements present, it can be concluded that the sample is a mixture of elements.Rate this question:
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- 3.
Which particle diagram below best represents a single element?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
A. AExplanation
Particle diagram A represents a single element because it shows only one type of particle. The other diagrams (B, C, and D) show a mixture of different types of particles, indicating that they represent compounds or mixtures rather than a single element.Rate this question:
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- 4.
A compound differs from a mixture in that a compound always has a
- A.
Minimum of three components
- B.
Heterogeneous composition
- C.
Homogeneous composition
- D.
Maximum of two components
Correct Answer
C. Homogeneous compositionExplanation
A compound differs from a mixture in that a compound always has a homogeneous composition. This means that the components of a compound are evenly distributed throughout the substance, resulting in a uniform appearance and properties. In contrast, a mixture can have a heterogeneous composition, where the components are not evenly distributed and may be visible as separate phases or layers. Therefore, the presence of a homogeneous composition is a key characteristic that distinguishes compounds from mixtures.Rate this question:
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- 5.
What process is used to separate a mixture of liquids based on differences in boiling points?
- A.
Distillation
- B.
Filtration
- C.
Titration
- D.
Chromatography
Correct Answer
A. DistillationExplanation
Distillation is the process used to separate a mixture of liquids based on differences in boiling points. In this process, the mixture is heated until one of the liquids reaches its boiling point and vaporizes, while the other components remain in liquid form. The vapor is then condensed and collected, resulting in the separation of the liquids. Filtration is used to separate solids from liquids, titration is a technique used to determine the concentration of a substance, and chromatography is used to separate different components in a mixture based on their affinity for a stationary phase.Rate this question:
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- 6.
A student observed the following reaction: After the products were filtered, which substance remained on the filter paper?
- A.
Substance A
- B.
Substance B
- C.
Substance C
- D.
Substance D
Correct Answer
B. Substance BExplanation
Based on the given information, the student observed a reaction and then filtered the products. Out of the substances listed, substance B is the one that remained on the filter paper after filtration.Rate this question:
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- 7.
Which is considered to be a chemical change?
- A.
Evaporating of rain water
- B.
Crushing ice
- C.
Decomposition of water into hydrogen and oxygen
- D.
Dissolving NaCl in water
Correct Answer
C. Decomposition of water into hydrogen and oxygenExplanation
The decomposition of water into hydrogen and oxygen is considered a chemical change because it involves the breaking of chemical bonds and the formation of new substances. In this process, water molecules are split into their constituent elements, hydrogen and oxygen, through a chemical reaction. This reaction is not reversible and results in the formation of two different substances with different properties than the original water molecules.Rate this question:
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- 8.
Which pahse change is endothermic?
- A.
Gas to liquid
- B.
Liquid to solid
- C.
Liquid to gas
- D.
Gas to solid
Correct Answer
C. Liquid to gasExplanation
The phase change from liquid to gas is endothermic because it requires the absorption of heat energy from the surroundings in order to overcome the intermolecular forces holding the liquid particles together and allow them to separate and form a gas. This absorption of heat causes the surrounding temperature to decrease.Rate this question:
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- 9.
Energy of position or stored energy is also called:
- A.
Chemical energy
- B.
Potential energy
- C.
Kinetic energy
- D.
Activation energy
Correct Answer
B. Potential energyExplanation
Potential energy refers to the energy possessed by an object due to its position or condition. It is often associated with the potential for work to be done when the object's position or condition changes. In this context, potential energy is synonymous with energy of position or stored energy. Chemical energy, on the other hand, refers specifically to the potential energy stored in the bonds of chemical compounds. Kinetic energy is the energy possessed by an object in motion, while activation energy refers to the minimum energy required for a chemical reaction to occur.Rate this question:
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- 10.
What unit is used to express the amount of energy absorbed or released during a chemical reaction?
- A.
Degree
- B.
Gram
- C.
Torr
- D.
Joule
Correct Answer
D. JouleExplanation
The unit used to express the amount of energy absorbed or released during a chemical reaction is the joule. The joule is a derived unit of energy in the International System of Units (SI). It is defined as the amount of work done when a force of one newton is applied over a distance of one meter. In the context of chemical reactions, the energy change is often referred to as the enthalpy change, and it is measured in joules.Rate this question:
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- 11.
What Kelvin temperature is the same as -13C?
- A.
260 K
- B.
747 K
- C.
286 K
- D.
773 K
Correct Answer
A. 260 KExplanation
The Kelvin temperature scale starts at absolute zero, which is -273.15 degrees Celsius. To convert Celsius to Kelvin, you simply add 273.15. Therefore, to find the Kelvin temperature that is the same as -13 degrees Celsius, you would add 273.15 to -13, resulting in 260.15 Kelvin. However, since Kelvin is typically rounded to the nearest whole number, the correct answer is 260 K.Rate this question:
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- 12.
As the temperature of a gas in increased, the average kinetic energy of its molecules
- A.
Increases
- B.
Decreases
- C.
Remains the same
Correct Answer
A. IncreasesExplanation
According to the kinetic theory of gases, the average kinetic energy of gas molecules is directly proportional to the temperature of the gas. As the temperature of a gas is increased, the molecules gain more energy and move faster, resulting in an increase in their average kinetic energy. Therefore, the correct answer is that the average kinetic energy of gas molecules increases when the temperature of the gas is increased.Rate this question:
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- 13.
Which beaker has the lowest kinetic energy?
- A.
A
- B.
B
- C.
C
- D.
D
Correct Answer
D. DExplanation
The beaker with the lowest kinetic energy is D because kinetic energy is directly proportional to the speed of the particles. Since D has the lowest speed among the given options, it will have the lowest kinetic energy.Rate this question:
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- 14.
The graph below represents the uniform cooling of a substance starting as a gas at 160 C. At what temperature does a phase change occure for this substance?
- A.
0*C
- B.
40*C
- C.
80*C
- D.
140*C
Correct Answer
B. 40*CExplanation
The graph shows the temperature of the substance decreasing uniformly from 160°C. A phase change occurs when the substance changes from one state to another, such as from a gas to a liquid or a liquid to a solid. In this case, the phase change occurs at 40°C, as indicated by the sudden change in the slope of the graph. Therefore, the correct answer is 40°C.Rate this question:
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