A solution is prepared by dissolving 215 grams of methanol, CH3OH, in 1000. grams of water. What is the freezing point of this solution? [The freezing point depression constant for water is 1.86°C/mole solute in 1000g of water]
The label on a 750 mL bottle of wine states that its alcohol content is 12% (v/v). What volume alcohol is present in the bottle?
MKTG2120 principles of marketing: chapter 12 IMC i…
They are all ionic compounds and They all dissociate completely.
Pressure has virtually no effect on the solubility of liquids or solids.
Solute A substance that is dissolved in another substance. Solvent Substances (usually liquid) capable of dissolving or dispersing one or more other substances. Soluble Capable of being dissolved in a solvent. Partially soluble When only part of a solute dissolves leaving the other part non-dissolved and usually still visible. Insoluble The inability of a substance to be dissolved in another substance. Ask students to discuss what they already know about solubility. Below are some sample questions: ● Can solids change into liquids? (Yes, by melting or dissolving in a liquid.) ● Does sugar dissolve in anything? (Yes, water. In this case, the sugar is called the solute and the water is called the solvent.) ● What is a solute? (Something that dissolves in a liquid.) ● What is a solvent? (A liquid in which something dissolves.) ● Are there liquids in which sugar does not dissolve? (Yes, oil.) ● How do you know when something has dissolved in a solvent? (You can’t see any more solid on the bottom of the cup of liquid.) Sometimes you need to look carefully at the solvent because the solute particles may be suspended but not dissolved in the liquid. Tell students that during the lab, they may need to wait a few minutes after adding solid to the solvent in order to determine if the solid particles will settle out of the suspension, or if they are really dissolved. During the remainder of the class, students should write up their procedures for conducting the solubility lab. Note that the current student worksheet sheet provides the lab objective and the materials list, but the rest of the lab is open-ended. It may be helpful to show students a sample setup with cups of solute, empty cups for solvent, and dispensers of water, alcohol, and oil. This may help them have a better idea of how to use these materials. Remind students that they do not need a large amount of solvent for each test (30-50 ml of solvent, roughly a Dixie cup filled roughly 2-3 cm, should work). A sample laboratory procedure is in included in Lab Answer Key. You may use this to help guide students who are having difficulty designing the experiment. Page 7 of 20 Why Follow the Water?
1) If you place a full cup of water out on a table in your classroom, will it start to boil? Why or why not? Water is stable to boiling at room temperature because the temperature is below the boiling temperature of the water at pressures found in the classroom.