Second Semester Final Reveiw

Which is an exothermic process?

• ice melting
• water boiling
• water evaporating
• water vapor condensing

Which statement correctly describes an endothermic chemical reaction?

• The products have higher potential energy than the reactants, and the energy is released into the environment.
• The products have higher potential energy than the reactants, and the energy is absorbed by the reaction.
• The products have lower potential energy than the reactants, and the energy is released into the environment.
• The products have lower potential energy than the reactants, and the energy is absorbed by the reaction.

Using the data below, what is the order of changes that occur when ethanol is heated from -25.0ºC to 85.0ºC? Boiling point of ethanol: 78.5ºC Melting point of ethanol: -117.3ºC

• Phase change, temperature change
• Phase change, temperature change, phase change
• Temperature change, phase change
• Temperature change, phase change, temperature change

Which of the following statements is true?

• In an endothermic process heat is transferred from the surroundings to the system.
• In an exothermic process heat is transferred from the surroundings to the system.
• The surroundings will feel cooler in an exothermic process.
• The surroundings will feel warmer in an endothermic process.

What would likely happen if you were to touch the flask in which an endothermic reaction were occurring?

• The flask would probably feel cooler than before the reaction started.
• The flask would probably feel warmer than before the reaction started.
• The flask would feel the same as before the reaction started.
• none of the above

Which of the following correctly matches the classification and bond type:

• Non-metals and non-metals: covalent bonds
• Non-metals and metals: covalent bonds
• Non-metals and metals: ionic bonds
• Both A and C

Alkali metals are extremely reactive because they

• have very small atomic masses.
• are not solids at room temperature.
• have one valence electron that is easily removed to form a positive ion.
• have two valence electrons that form compounds with calcium and magnesium.

Most halogens form compounds by

• gaining an electron to form a negative ion.
• losing an electron to form a positive ion.
• losing protons.
• joining with both calcium and carbon.

Why do atoms share electrons in covalent bonds?

• to become ions and attract each other
• to attain a noble-gas electron configuration
• to become more polar
• to increase their atomic numbers

Which of the following occurs in an ionic bond?

• Oppositely charged ions attract.
• Two atoms share two electrons.
• Two atoms share more than two electrons.
• Like-charged ions attract.