Electrolytes Lab Report PDF

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Electrolytes Lab Report...

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Name: Gabriella Molinari Lab: Electrolytes Date: 02/28/2021 Introduction: The objective of this lab is to understand the electrical conductivity of solutions by a lightbulb method. The lightbulb method would be how brightly the lightbulb shines in order to determine whether the electrolyte is weak, strong, or a non-electrolyte. Electrolytes Preliminary Questions (10 points) 1. Classify each of the following a strong, weak or non-electrolytes: nitric acid, sulfuric acid, potassium hydroxide, calcium hydroxide, methylamine (an ammonia derivative), benzoate acid, salicylic acid, glucose, and oxygen gas. Nitric acid ___________strong electrolyte___________ Sulfuric acid __________ strong electrolyte____________ Calcium hydroxide _________ strong electrolyte_____________ Potassium hydroxide ___________ strong electrolyte___________ Methylamine (an ammonia derivative) _________ weak electrolyte_____________ Benzoic acid ___________ weak electrolyte___________ Salicylic acid _________ weak electrolyte_____________ Glucose __________ non-electrolyte____________ Oxygen gas __________ non-electrolyte____________ 2. Define the term weak electrolyte. A weak electrolyte is an electrolyte that does not ionize well in water and will not conduct a very electrical current. 3. What is the proper disposal of the salt solutions in this experiment? You should dispose of the salt solutions in the waste salt solutions bottle. Chemical Responsibility: 1. Calcium chloride, CaCl2- no major health risks 2. Sodium chloride, NaCl- no major health risks 3. Ammonium chloride, NH4Cl- toxic by ingestion 4. Sodium sulfite, Na2SO3- irritant 5. Glucose or dextrose, C6H12O6- no major health risks 6. Sucrose, C12H22O11- no major health risks 7. Ethanol, C2H5OH- flammable liquid and toxic 8. Methanol, CH3OH- flammable liquid and toxic 9. Hydrochloric acid, HCl- toxic, corrosive, and may cause burns 10. Acetic acid, HC2H3O2- corrosive, toxic and may cause burns

11. Ammonia, NH3- toxic, corrosive, may cause permanent fogging of soft contact lenses, and respiratory irritant 12. Sodium hydroxide, NaOH- corrosive, toxic and may cause burns The protection needed for these chemicals are to wear goggles, wear protective clothing, wear protective gloves, wear a mask, and to keep away from the flame. Electrolytes Report Sheet (30 Points) NaCl CaCl2 NH4Cl 3 M HCl 3 M NaOH 3 M acetic acid 3 M ammonia Upon mixing the acetic acid and ammonia Sugar Alcohol

strong electrolyte strong electrolyte strong electrolyte strong electrolyte strong electrolyte weak electrolyte weak electrolyte strong electrolyte non-electrolyte non-electrolyte

Dilution Effects: NaCl (before dilution) After adding 100 mL H2O After adding 200 mL H2O After adding 300 mL H2O After adding 400 mL H2O After adding 500 mL H2O After adding 600 mL H2O

strong electrolyte strong electrolyte strong electrolyte strong electrolyte strong electrolyte strong electrolyte strong electrolyte

(Even though the NaCl is still a strong electrolyte with H2O, the light on the lightbulb became weaker with every addition of 100 mL H2O.) Electrolytes Post-Lab Questions (50 points) 1) Although ammonia and acetic acid themselves are weak electrolytes, a mixture of these two solutions behaved as a strong electrolyte. Why? Since both ammonia and acetic acid are both weak electrolytes. When the two are mixed together, a proton is extracted from the acetic acid and leads to a strong acid, and changes he substance to a strong electrolyte. 2) Write the reaction that occurs when ammonia and acidic acid are mixed. NH3 + CH3COOH = CH3COONH4

3) In one portion of this experiment you added a pinch of NaCl to a beaker, and you added progressively more and more water to the beaker. Explain why the light gets dimmer and dimmer. Electrolytes produce ions when dissolved in water. Electrical conductivity of water depends on the amount of ions. So when you dilute a solution, the number of NaCl ions is reduced. This makes the light become dimmer. 4) You are given three bottles labeled a, b, and c. The bottles contain pentane (C5H12, a liquid), calcium chloride (CaCl2) solution, and aqueous ammonium hydroxide (NH4OH, ammonia dissolved in water). Describe a procedure to identify which liquid would be in each bottle. We can distinguish them by measuring their conductivity. By dissolving Pentane we won't get ions, Calcium chloride we get 3 ions & aqueous ammonium hydroxide we get 2 ions. 5) The device used in this experiment only measured the relative conductivity of the solution tested, that is, whether the solution contained a strong, weak or nonelectrolyte. A more elaborate conductivity meter can determine a numerical value that can be related to the number of ions in solution. Arrange the following 0.1 M solutions in order of increasing conductivity and explain why you chose this order. 0.1 M FeCl3 0.1 M MgCl2 0.1 M NaCl 0.1 M glucose (C6H12O6) Conductivity is directly proportional to the number of ions in the solution. Glucose doesn’t form any ions in the solution, so it has the lowest conductivity in the group. If we go by the number of ions, the order of 0.1 M solutions would be 0.1 M glucose (C6H12O6)< 0.1 M NaCl...