This lab will be performed but I need help coming up with a procedure and identi

Question

This lab will be performed but I need help coming up with a procedure and identifying the unknown. The unknowns will include: sodium hydroxide, potassium hydroxide, ammonium chloride, sodium acetate, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, potassium hydrogen carbonate, and potassium hydrogen phosphate.
Also, what do all the potential white solids have in common?
Any help will be greatly appreciated, thank you. PROJECT 9: WHITE POWDERS You work in a pet store, and as part of your job you are required to keep the fish tanks clean and operational. Your instructions for doing this require that each week you add 100 g of “water conditioner" (a white solid) to the tank to maintain the correct pH and ionic strength. All goes well until one week you add the white solid to the fish tank and within 24 hours all the fish die. Clearly someone has replaced the innocuous "water conditioner" with something that is toxic to fish. It is your job to discover exactly what this material is. You send the powder off for analysis, and the results show that there are no heavy metals and only common ions in the compound. In the pet store you do not have much in the way of an analysis lab, but you do have standardized solutions of hydrochloric acid and sodium hydroxide and a pH meter Your job is to figure out what the white solid is and form a hypothesis about why it might have killed the fish. The stockroom inventory tells you that at one time or another the pet store has had samples of sodium hydroxide, potassium hydroxide, ammonium chloride, sodium acetate, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, potassium hydrogen carbonate, and potassium hydrogen phosphate. Available materials: 5 grams white solid 1 M, 3 M, 6 M HCI 1 M, 3 M NaOH pH meter, range of indicators, pH paper Safety Notes .Be sure to consult the MSDS for any compound that you work with. Wear safety goggles and appropriate clothing at all times in the laboratory Dispose of wastes in the labeled containers. Do not pour any wastes down the drain. Use great care when transferring solutions of strong acids and bases. Techniques You May Need to Learn or Review Use of pH meter Titration .Use of volumetric glassware Section 5 Projects

Explanation / Answer

The material according to me is ammonium chloride which has a pH between 4 to 6 i.e acidic. All the other white solids have pH greater than 7. For aquatic life to sustain pH of the water should be high. But on addition of ammonium chloride to water, lowers the pH of water and an increases molarity of ammonium chloride is enough to kill the fishes within 24 hrs.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.