Chapter 2: Adaptive Study Plan

Which of the following is false? 1) Two objects, both having positive charge, repel each other. 2) Two objects having unlike charges attract each other. 3) Electrostatic forces are responsible for the energy absorbed or released in chemical changes. 4) The region in space where magnetic or electrostatic forces are effective is called a force field. 5) All of the above are true.

5) ??**check with prof***

Which of the following statements is false? A) As a positively charged object moves toward a negatively charged object, their potential energy increases. B) As a positively charged object moves toward another positively charged object, their potential energy increases. C) As a negatively charged object moves toward another negatively charged object, their potential energy increases. D) Increasing the distance between two electrically charged objects may raise or lower their potential energy. E) All of the above are true.

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what is a chemical compound?

A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions.

heterogeneous mixture

A mixture in which different materials can be distinguished easily

Which one of the following properties of nitrogen is a chemical property? A) It reacts with oxygen at high pressure B) Gas at room temperature C) Colorless D) Density = 1.25 g/L E) Boils at 77K

A)

A) Water freezes at 0ºC and 1 atm pressure. B) Water and oil do not mix. C) Water reacts with sodium metal. D) Water boils at 100ºC and 1 atm pressure. E) The density of water is 1 g/mL. Which of the following is not a physical property?

C)

Which species below is a chemical compound? A) S8 B) Os C) HF D) O3 E) Br2

C)

Which of the following is a heterogeneous mixture? A) hot coffee B) carbon tetrachloride C) cereal with milk D) bottled water E) vodka

C) cereal with milk

__________ are substances with constant composition that can be broken down into elements by chemical processes.

Compounds

Which of the following statements is false? A) The potential energy of an object depends on its position in a field where forces of attraction and/or repulsion are present. B) Any moving object has kinetic energy. C) Minimization of energy is one of the driving forces that cause chemical reactions to occur. D) Kinetic energy is always greater than potential energy for an object. E) Most of what we call "mechanical energy" is kinetic energy.

D)

Which one of the following does not have a fixed shape or a fixed volume? A) Marble B) Blood C) Sugar D) Nitrogen E) Water

D)

If you had a homogeneous mixture of ethyl alcohol and water, what method would you use to obtain pure ethyl alcohol?

Distillation

Which of the following is the best statement of the Law of Conservation of Mass? A) In any non-nuclear change, energy is conserved. B) In a chemical change, the mass of the reactants is always greater than or equal to the mass of the products. C) In a chemical change, the mass of the products is always greater than or equal to the mass of the reactants. D) For endothermic chemical reactions, the mass of the products is greater than the mass of the reactants, and for exothermic chemical reactions, the mass of the products is less than the mass of the reactants. E) In a chemical change, mass is neither created nor destroyed.

E)

An example of a pure substance is A) elements. B) compounds. C) carbon dioxide. D) pure water. E) All of these choices are correct.

E) All of them: elements, compounds, pure water, carbon dioxide

Color changes always indicate a chemical change T or F

False

Boiling is the process by which a liquid becomes a

GAS

Why is the law of definite proportions important?

The Law of Definite Proportions ensures that chemical compounds are always created using the same proportions, regardless of the amount of the compound which is being made.

Homogenous mixture

a mixture in which the composition is uniform throughout

The state of matter that has a definite volume and rigid shape is called

a solid

The simplest pure substance is called

an element.

Peanuts and popcorn form what kind of mixture?

heterogeneous mixture

Filtration can be used to separate

heterogeneous mixtures

The state of matter for an object that has a definite volume but not a definite shape is:

liquid state.

Is a cat hair macroscopic, microscopic, or particulate?

macroscopic

Is a plant cell macroscopic, microscopic, or particulate?

microscopic

Is a protein molecule macroscopic, microscopic, or particulate?

particulate