CCSD Phy Sci HS Unit 4 Interim

Based on the models, which of the following could a student predict to be the formula of potassium iodide?

• I₇K

• K₇I

• KI

• IK

What is the correct name for the compound formed?

• A. Bromium calcide

• B. Calcium bromide

• C. Calcium hexabromide

• D. Monocalcium hexabromide

A light bulb is connected with a battery and two electrodes that are immersed in a water solution. The composition of the solution and the state of the light bulb (lit or unlit) is indicated by the data in the table. What is the BEST explanation for the results shown in the table and why? | Solute | Solubility in Water | State of the Light | |-------------------|---------------------|--------------------| | Sodium Chloride | Very soluble | Light bulb is lit | | Sugar | Very soluble | Light bulb is not lit | | Starch | Soluble | Light bulb is not lit | | Potassium Iodide | Very soluble | Light bulb is lit | A. The sugar and starch solutions do not have a high enough concentration to allow the solution to conduct electricity. B. The sodium chloride and potassium iodide dissolve to form positive and negative ions, which allow the solution to conduct electricity. C. The sugar and starch dissolve to form positive and negative ions; however, the concentration of ions is not sufficient to conduct electricity. D. The sodium chloride and potassium chloride are both very soluble. Thus, the solutions have a high enough concentration to allow the solution to conduct electricity.

• A. The sugar and starch solutions do not have a high enough concentration to allow the solution to conduct electricity.

• B. The sodium chloride and potassium iodide dissolve to form positive and negative ions, which allow the solution to conduct electricity.

• C. The sugar and starch dissolve to form positive and negative ions; however, the concentration of ions is not sufficient to conduct electricity.

• D. The sodium chloride and potassium chloride are both very soluble. Thus, the solutions have a high enough concentration to allow the solution to conduct electricity.

What is the coefficient for H₂O when the above equation is balanced?

• 1

• 2

• 3

• 4

According to the law of conservation of mass, how much zinc is present after the reaction and how does this compare to the amount of zinc present before the reaction?

• 64 g of zinc is present after the reaction. This is the same as the amount of zinc present before the reaction.

• 64 g of zinc is present after the reaction. This is less than the amount of zinc present before the reaction.

• 104 g of zinc is present after the reaction. This is the same as the amount of zinc present before the reaction.

• 104 g of zinc is present after the reaction. This is more than the amount of zinc present before the reaction.

What factor, when changed, would produce the most effective circumstances for a faster solution?

• Use larger solute pieces, because larger particles decrease the surface area, therefore increasing the rate of solubility.

• Leave the solution undisturbed, because lower agitation decreases collisions, therefore increasing the rate of solubility.

• Crush the solute into more pieces, because smaller particles increase the surface area, therefore increasing the rate of solubility.

• Decrease the temperature, because a lower temperature will decrease the kinetic energy, and therefore increase the rate of solubility.

Based on the information here, if 100 grams of the salt KBr is added to 100 mL of water at 90°C, how would this solution be best classified?

• Insoluble

• Saturated

• Unsaturated

• Supersaturated

Which chemical name correctly reflects the IUPAC naming convention for the compound SO₂?

• sulfur oxide

• sulfide oxide

• sulfur dioxide

• sulfur dioxygen

When presented with a model of a solution that successfully conducts electricity to light a lightbulb, a student is asked to design a model of a solution that would have even greater conductivity. Based on the model of the control, which experimental model would BEST demonstrate an increase in the conductivity of the solution?

• a beaker with the same ions and sucrose molecules but with more water

• a beaker with the same ions and sucrose molecules but with less water

• a beaker with no ions or sucrose molecules and the same amount of water

• a beaker with the same number of ions but with more sucrose molecules

Which statement BEST describes the pH and structure of the mystery substance?

• The mystery solution has a pH less than 7, because it releases hydrogen ions (H+) when dissolved in water, increasing the concentration of H+ ions in a solution.

• The mystery solution has a pH less than 7, because it releases hydroxide ions (OH-) when dissolved in water, increasing the concentration of OH- ions in a solution.

• The mystery solution has a pH greater than 7, because it releases hydrogen ions (H+) when dissolved in water, increasing the concentration of H+ ions in a solution.

• The mystery solution has a pH greater than 7, because it releases hydroxide ions (OH-) when dissolved in water, increasing the concentration of OH- ions in a solution.