Question

exploring properties of water
directions: write all answers on the next sheet of paper. write in complete sentences, and thoroughly explain your answer for credit.

1. sodium pentothal, also known as truth serum, is used by the c.i.a. to gather intel from high - profile criminals/terrorists. one way to inconspicuously get the criminal of interest to ingest the serum is to slip it into their drink. sodium pentothal is a compound created chemically combining a metal and a nonmetal. your mom is a cia agent, and you discovered some truth serum from her coat pocket. you suspect that your boyfriend or girlfriend is cheating on you after snooping through their phone. you then have an “aha” moment, and decide to use the truth serum on your boyfriend/girlfriend. to use it, you must slip it into their water bottle without them knowing. once they finish their water, they will tell you their deepest, darkest secrets within 30 minutes. when placed in a water - based liquid, the sodium pentothal compound disappears.

a. what type of mixture is formed when the sodium pentothal mixes with water? explain. homogeneous mixture.
b. describe how the water causes the truth serum to disappear. use the terms polar, positive ions, negative ions, solute, and solvent in your answer.

Explanation:

a. Sodium pentothal dissolves uniformly in water, creating a single - phase mixture with consistent composition throughout, which is the definition of a homogeneous mixture.
b. Water is a polar solvent. Sodium pentothal, the solute, is an ionic compound. When placed in water, the polar water molecules surround the positive and negative ions of the sodium pentothal. The positive ends of water molecules are attracted to the negative ions of the solute and the negative ends of water molecules are attracted to the positive ions of the solute. This process, called hydration, causes the sodium pentothal to break apart and disperse evenly in the water, making it seem to disappear.

Answer:

a. A homogeneous mixture is formed because the sodium pentothal dissolves uniformly in water creating a single - phase system with consistent composition.
b. Water is a polar solvent. The positive and negative ends of water molecules attract the positive and negative ions of sodium pentothal (the solute). Through hydration, the solute breaks apart and disperses evenly in the water, making it seem to disappear.