7AE_Chemistry End-term test

A student added four substances to water placed in separate glass containers. She recorded the solubility of the substances as the temperature of the water was heated and graphed the results.

What do the graphs she created help demonstrate?

• The solubility of solids and gases in water increases as the temperature increases.

• The solubility of solids and gases in water decreases as the temperature increases.

• The solubility of solids in water increases, but the solubility of gases decreases as the temperature increases.

• The solubility of solids in water decreases, but the solubility of gases increases as the temperature increases.

The diagram models bonding in chlorine gas, Cl₂, and sodium chloride, KCl. Which statement accurately compares ionic and covalent bonding?

• The attractive forces between molecules are weaker than those between ions because valence electrons are shared.

• The attractive forces between molecules are stronger than those between ions because valence electrons are shared.

• The attractive forces between molecules are weaker than those between ions because valence electrons are transferred.

• The attractive forces between molecules are stronger than those between ions because valence electrons are transferred.

Which property is dependent only on the atomic structure of the compound?

• mass

• volume

• melting point

• total thermal energy

Which statement is correct about changes in solubility of gases and solids in liquids?

• The solubility of gases and solids changes with pressure.

• The solubility of gases but not solids changes with pressure.

• The solubility of solids but not gases changes with pressure.

• The solubility of gases and solids does not change with pressure.

Ethylene is a compound used in the production of polyethylene, a widely used plastic. The chemical formula for ethylene is C2H4. There is a double bond between the two carbon atoms.

How does the three-dimensional arrangement of ethylene affect its polarity?

• The C–H dipoles cancel to make ethylene a polar molecule.

• The C–H dipoles combine to make ethylene a polar molecule.

• The C–H dipoles cancel to make ethylene a nonpolar molecule.

• The C–H dipoles combine to make ethylene a nonpolar molecule.

A company needs a plastic that is lightweight and flexible but doesn’t need to withstand impacts or other tests of strength. Which polymer structure would best suit the company’s needs?

• linear

• branched

• networked

• cross-linked

The diagram models metallic bonding. What about the electrons in metal elements contributes to metallic bonding?

• All electrons move within pairs of atoms.

• All electrons are attracted to several nuclei.

• Outer electrons are able to move freely within the sample.

• Outer electrons are tightly held by the nucleus in each atom.

What would be the general formula unit of a compound made with a Group 1 element, A, and a Group 16 element, Z, from the periodic table? Refer to the periodic table.

• AZ

• AZ₂

• AZ₁₆

• A₂Z

A block of steel rests on a table. Which action will increase the internal kinetic energy of the block?

• Drop it on the floor.

• Raise it off the table.

• Slide it across the table.

• Heat it to a greater temperature.

Raymundo uses the following recipe to make fresh lemonade.

9 lemons + 2 cups sugar + 12 cups water → 1 pitcher of lemonade

He has 72 lemons, 18 cups of sugar, and plenty of water. Raymundo will make pitchers of lemonade until he runs out of one of the ingredients. How many pitchers will Raymundo make?

• 8 pitchers because he will run out of sugar first

• 8 pitchers because he will run out of lemons first

• 9 pitchers because he will run out of sugar first

• 9 pitchers because he will run out of lemons first