What is the evidence that a solution is saturated? Postlab Session

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Transcript of What is the evidence that a solution is saturated? Postlab Session

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What is the evidence that a solution is saturated? Postlab Session Slide 2 Recap What is a solution? What are the properties of solutions? How can particles of a solution pass through the filter paper? Why does a solution have a uniform appearance? Slide 3 Pop Quiz! 1. What is the title of Activity No. 3? 2. Give one objective for the activity. 3. What was the solid solute used in the activity? 4. How much water was placed on the container before the start of the activity? 5. How many times should an experiment be done to be sure of the data gathered? Slide 4 1. What is the title of Activity No. 3? What is the evidence that a solution is saturated? Slide 5 2. Give one objective of the activity. Determine how much solid solute dissolves completely in a given volume of water; Describe the appearance of a saturated solution. Slide 6 3. What was the solid solute used in the activity? sugar Slide 7 4. How much water was placed on the container before the start of the activity? 50 mL Slide 8 5. How many times should an experiment be repeated to be sure of the result of the experiment? At least 3 times Slide 9 Procedures Place 50 mL water in a clear container. Add teaspoon sugar into the water and dissolve it. Continue adding teaspoon of sugar until the sugar would not dissolve anymore. Repeat the steps at least 3 times to check whether the results are acceptable or not. Slide 10 Accurate or Precise? Olga is tasked by her groupmates to determine the mass of a 100-gram metal. Upon using the triple beam balance, she got the following measurements after three trials:95.12 grams, 95.20 grams, and 94.96 grams. Is the triple beam balance precise or accurate in its measurements? Slide 11 Critical points Accurate measurements are compared against a reference or accepted value. Precise refers to how close the measurements to each other. Slide 12 Going back Olga is tasked by her groupmates to determine the mass of a 100-gram metal. Upon using the triple beam balance, she got the following measurements after three trials:95.12 grams, 95.20 grams, and 94.96 grams. Is the triple beam balance precise or accurate in its measurements? Accurate? Precise? Slide 13 Which is more important in experiments? Accuracy of precision? Slide 14 Going back After calibrating the triple beam balance, Olga measured again the 100-gram metal and got the following measurements: 100.1 grams, 100.0 grams, 99.99 grams. Are the data accurate or precise? Slide 15 Meanwhile Amount of SugarObservations After adding teaspoon of sugar The sugar is dissolved completely. teaspoon of sugarThe sugar is dissolved completely. teaspoon of sugarThe sugar is dissolved completely. 1 teaspoon of sugarThe sugar is dissolved completely. 1 teaspoon of sugarThe sugar is dissolved completely. 1 teaspoon of sugarThe sugar is dissolved completely. 1 teaspoon of sugarThe sugar is dissolved completely. Slide 16 After adding more Amount of SugarObservations 4 teaspoons of sugarThe sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugarThe sugar is dissolved completely. 5 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugar Sugar doesnt dissolve anymore. Slide 17 Why wouldnt the sugar dissolve in water? There is a MAXIMUM AMOUNT of solute that can dissolve in a given amount of solvent at a given temperature. Slide 18 What is the maximum amount of sugar that can dissolve in 50 mL water at room temperature? Amount of SugarObservations 4 teaspoons of sugarThe sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugarThe sugar is dissolved completely. 5 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugar Sugar doesnt dissolve anymore. Slide 19 When the solvent contains the MAXIMUM AMOUNT of solute that it can dissolve, it is a called SATURATED SOLUTION. Slide 20 What is a SATURATED SOLUTION? A SATURATED SOLUTION is a solution that contains the MAXIMUM AMOUNT of solute that the solvent can dissolve. Slide 21 How would you know that a solution is saturated? Amount of SugarObservations 4 teaspoons of sugarThe sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 4 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugarThe sugar is dissolved completely. 5 teaspoons of sugar The sugar is dissolved completely. 5 teaspoons of sugar Sugar doesnt dissolve anymore. What happens when you add more solute to a saturated solution? Slide 22 What is the evidence that a solution is saturated? The presence of excess solute which can no longer dissolve is an evidence that a solution is saturated. Slide 23 What is an UNSATURATED SOLUTION? SATURATED SOLUTION Slide 24 A solution is UNSATURATED when it contains LESS SOLUTE than the MAXIMUM AMOUNT it can dissolve in a given temperature. Slide 25 Summing up A SATURATED SOLUTION is a solution that contains the MAXIMUM AMOUNT of solute that the solvent can dissolve. The presence of excess solute which can no longer dissolve is an evidence that a solution is saturated. A solution is UNSATURATED when it contains LESS SOLUTE than the MAXIMUM AMOUNT it can dissolve in a given temperature. Slide 26 How would you know which of these solutions is SATURATED? 50 grams of salt in 20 mL water 50 grams of sugar in 20 mL water Slide 27 Moving forward The MAXIMUM AMOUNT of solute that can dissolve in a given volume of solvent at a given temperature is called the SOLUBILITY OF THE SOLUTE. Slide 28 The solubility of salt at 25 0 C is 36 grams in 100 mL of water. The MAXIMUM AMOUNT of solute that can dissolve in a given volume of solvent at a given temperature is called the SOLUBILITY OF THE SOLUTE. Slide 29 Describe the following solutions. 1. 15 grams of salt in 100 mL of water 2. 30 grams of salt in 100 mL of water 3. 36 grams of salt in 100 mL of water 4. 60 grams of salt in 200 mL of water 5. 72 grams of salt in 200 mL of water The solubility of salt at 25 0 C is 36 grams in 100 mL of water. Slide 30 Ricky was trying to determine the solubility of salt in 100 mL of water. He did three trials and got the following results: First TrialSecond TrialThird Trial 35.83 grams36.24 grams36.07 grams Accurate or Precise? Slide 31 A group of students were able to gather the following data and observations after dissolving sugar in 100 mL of water. StepAmount of Solute added Observations 11 teaspoonAfter stirring, sugar dissolves completely. 21 teaspoonAfter stirring, sugar dissolves completely. 31 teaspoonAfter stirring, sugar dissolves completely. 41 teaspoonAfter stirring, sugar dissolves completely. 51 teaspoonAfter stirring, some sugar is seen at the bottom of the container Slide 32 True or False? 1. An unsaturated solution is a solution that contains the maximum amount of solute that can be dissolved. 2. The presence of excess solute that can no longer be dissolved is an evidence that the solution is saturated. 3. The maximum amount of solute that can dissolve in a given volume of solvent at a given temperature is called the solubility of the solvent. Slide 33 Reminders! Please do advance reading of our lessons through your text. Chapter 5 (Solutions) Checking of textbooks on Monday. Ensure that you have your books on that date. Bring a calculator on the next session. It DOESNT have to be a scientific calculator.