Solutions cheat sheet
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This document provides a cheat sheet on key concepts regarding solutions in chemistry. It defines important solution terms like solute, solvent, saturated and supersaturated solutions, and concentration. It describes methods for calculating concentration as percentages by mass/volume and using molarity and molality. Factors that affect solubility like temperature, pressure and "like dissolves like" are summarized. Equations for dilution and using molarity in stoichiometric calculations involving solutions are presented. The formation of solutions and electrolyte solutions are briefly outlined. Colloids are defined as solutions that scatter light, exhibiting the Tyndall effect.
Solutions cheat sheet
- 1. High School Chemistry - Core Concept Cheat Sheet 19: Solutions Key Solution Terms Concentrations of Solution Solution: Homogeneous mixture. The solution formation involves the breaking and forming of intermolecular forces. Solution = Solute + Solvent. Solute: Substance being dissolved (in smaller amount). % by mass: % mass mass solute 100 mass solution The mass units must match! Solvent: Substance doing the dissolving (in larger amount). Solute vs Solvent Mnemonic: Dissolve solute into solvent = “Police came, the thief hide the lute in the vent.” % by volume: % volume volume solute 100 Unsaturated Solution: The solution can hold more solute particles. % mass/volume: % mass / volume mass solute 100 volume solution The volume unit is mL. Saturated Solution: The solution is holding as many solute particles as it can. Supersaturated Solution: The solution contains more solute particles than it should be able to at that temperature. A solution can become supersaturated by raising the temperature, which allows more solute to dissolve, and then lowering the temperature slowly back down. Concentration: ratio of solute to solvent or solution. Concentrated: high ratio of solute to solvent. Solubility Curve: Graph showing the solubility of a solid at various temperatures. Dilute: low ratio of solute to solvent. Dilution: adding solvent to create a more dilute solution. Electrolyte: compounds dissociate into ions when dissolved in water. Allows solution to conduct electricity. Colloids: Solution with solute particles large enough to exhibit the Tyndall Effect. Tyndall Effect: The light is visible and scattered as it travels through the colloid. Molarity (M): Molarity moles solute L solution Molality (m): Molality moles solute kg solvent Molarity vs Molality Mnemonic: MolaRity (moles over Liter solution) and MolaLity (moles over kg solvent) = “Rose to Lover and Loyal to King!” Calculations with Concentrations Dilution equation: M1V1 = M2V2 M1 = original molarity V1 = original volume M2 = new molarity V2 = new volume Volume units must match! Solution Stoichiometry: Use molarity to form the equality between moles and liters of a solution. Example: How many liters of 1.7M HCl are needed to react with 2.5 g Mg? 2.5g Mg Formation of Solutions Steps for solution formation: 1. “Expand the solvent”—break intermolecular forces within the solvent. 2. “Expand the solute”—break intermolecular forces within the solute. 3. Form new intermolecular forces between solute & solvent. Steps 1 & 2 require energy. Step 3 releases energy. If the energy put in is much greater than the energy released, the solution will not form. Factors Affecting Solubility “Like Dissolves Like” Molecules with “like” bond properties will form similar intermolecular forces with each other as they did with themselves. Therefore, the energy released will be similar to the energy put in. Pressure: Gases dissolve more when there is a higher pressure of the gas above the solution. Temperature: Gases dissolve more when the temperature of the solution is lower. Most solids dissolve more when the temperature of the solution is higher. How to Use This Cheat Sheet: These are the keys related to this blank sheet of paper. Review it again before the exams. RapidLearningCenter.com volume solution The volume units must match! 1 mole Mg 24.31 g Mg 2 mole HCl 1 mole Mg 1 L HCl 1.7 mole HCl = 0.12 L HCl Electrolyte Solutions To break up into electrolytes: Leave polyatomic ions together. Use subscripts that are not a part of a polyatomic ion as coefficients. Examples: NaNO3 Na+ + NO3CaCl2 Ca2+ + 2 Cl- Colloids Colloids - Solutions with large enough particles to scatter light. Tyndall effect: For a solution: For a colloid: topic. Try to read through it carefully twice then recite it out on a Rapid Learning Inc. All Rights Reserved