Titration Lab Results and pH

In this segment, the students discuss the data from their titration lab. Our host explains the importance of titration in real world applications and discusses auto ionization of water and the calculation of pH.

In this segment, the students discuss the data from their titration lab. Our host explains the importance of titration in real world applications and discusses auto ionization of water and the calculation of pH.

Premiere Date: August 7, 2016 | Runtime: 00:07:42

Toolkit

Unit 7I Note Taking Guide & Segment Questions
Unit 7I Practice Problems 1- pH Calculations
Unit 7I Practice Problems 2- pH Calculations

Crosscutting Concepts

System and System Models

Defining the system under study—specifying its boundaries and making explicit a model of that system—provides tools for understanding and testing ideas that are applicable throughout science and engineering.

Stability and Change

For natural and built systems alike, conditions of stability and determinants of rates of change or evolution of a system are critical elements of study.

Science & Engineering Practices

Analyzing and Interpreting Data

Once collected, data must be presented in a form that can reveal any patterns and relationships and that allows results to be communicated to others. Because raw data as such have little meaning, a major practice of scientists is to organize and interpret data through tabulating, graphing, or statistical analysis. Such analysis can bring out the meaning of data—and their relevance—so that they may be used as evidence.
Engineers, too, make decisions based on evidence that a given design will work; they rarely rely on trial and error. Engineers often analyze a design by creating a model or prototype and collecting extensive data on how it performs, including under extreme conditions. Analysis of this kind of data not only informs design decisions and enables the prediction or assessment of performance but also helps define or clarify problems, determine economic feasibility, evaluate alternatives, and investigate failures. (NRC Framework, 2012, p. 61-62)

Constructing Explanations and Designing Solutions

The goal of science is the construction of theories that provide explanatory accounts of the world. A theory becomes accepted when it has multiple lines of empirical evidence and greater explanatory power of phenomena than previous theories.”(NRC Framework, 2012, p. 52)

Engaging in Argument from Evidence

The study of science and engineering should produce a sense of the process of argument necessary for advancing and defending a new idea or an explanation of a phenomenon and the norms for conducting such arguments. In that spirit, students should argue for the explanations they construct, defend their interpretations of the associated data, and advocate for the designs they propose. (NRC Framework, 2012, p. 73)

Generating a Hypothesis and Developing a Model

Modeling can begin in the earliest grades, with students’ models progressing from concrete “pictures” and/or physical scale models (e.g., a toy car) to more abstract representations of relevant relationships in later grades, such as a diagram representing forces on a particular object in a system. (NRC Framework, 2012, p. 58)

Using Mathematics and Computational Thinking

Although there are differences in how mathematics and computational thinking are applied in science and in engineering, mathematics often brings these two fields together by enabling engineers to apply the mathematical form of scientific theories and by enabling scientists to use powerful information technologies designed by engineers. Both kinds of professionals can thereby accomplish investigations and analyses and build complex models, which might otherwise be out of the question. (NRC Framework, 2012, p. 65)

Vocabulary

acid - substances that ionize in solutions to form H^+ ions.

amphoteric - a substance that can be an acid or a base.

Arrhenius Model - in aqueous solutions, acids form hydrogen ions (H^+).

base - substances that ionize in solutions and form OH^- ions.

binary acids - acids that do not contain oxygen in their chemical formula.

boiling point elevation - occurs when the boiling point of a solution is higher than the boiling point of the pure solvent alone.

Bronsted-Lowry Model - this model states that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a base.

colligative properties - properties of the solution that are different than those of a pure solvent by itself.

dilution - the process of adding more solvent to a solution.

electrolysis - the decomposition of water.

freezing point depression - a colligative property that describes how the freezing point of a solution is lowered compared to the freezing point of the pure solvent.

heterogeneous mixture - a combination of two or more substances in which the original substances are separated into physically distinct regions with differing properties.

homogeneous mixture - a combination of two or more substances that have uniform composition and chemical properties throughout; also known as a solution.

insoluble - a solid, liquid, or gas that will not dissolve in a particular solvent.

Lewis Model - bases donate pairs of electrons and acids accept pairs of electrons.

mass percent - a way of expressing how concentrated a solution is; is equal to the mass of the solute in a solution divided by the total mass of the solution and multiplying by 100.

mixture - a combination of two or more pure substances in which each pure substance retains its individual chemical properties.

molality - a ratio of moles of solute to the mass of the solvent in kilograms.

molarity - a ratio of moles of solute to the volume of the solution in liters.

oxyacids - acids that contain oxygen in their chemical formula.

pure substance - a material that has a constant composition and has consistent properties throughout the sample.

saturated solution - a solution in which the maximum amount of solute has been dissolved in a given amount of solvent at a particular temperature.

saturation point - the point at which no more solute can be dissolved in the solution at that particular temperature.

solubility - the maximum amount of a substance that can be dissolved in a given quantity of solvent at a given temperature to produce a saturated solution.

solute - the substance that is being dissolved in a solution.

solution - a liquid mixture in which the solute is uniformly distributed within the solvent.

solvent - the substance that is present in a greater amount in a solution.

supersaturated solution - a solution that is holding more dissolved solute than what it normally would hold at that temperature.

Georgia Standards of Excellence

SC6Obtain, evaluate, and communicate information about the properties that describe solutions and the nature of acids and bases.

SC6.fUse mathematics and computational thinking to compare, contrast, and evaluate the nature of acids and bases in terms of percent dissociation, hydronium ion concentration, and pH. (Clarification statement: Understanding of the mathematical relationship between negative logarithm of the hydrogen concentration and pH is not expected in this element. Only a conceptual understanding of pH as related to acid/basic conditions is needed.)

SC6.hPlan and carry out an investigation to explore acid-base neutralization.

SPS6Obtain, evaluate, and communicate information to explain the properties of solutions.

SPS6.dObtain and communicate information to explain the relationship between the structure and properties (e.g., pH and color change in the presence of an indicator) of acids and bases. (Clarification statement: Limited to only the structure of simple acids and bases (e.g., HCl and NaOH) that demonstrates the presence of an H+ or OH-.

SPS6.ePlan and carry out investigations to detect patterns in order to classify common household substances as acidic, basic, or neutral.

Request Teacher Toolkit

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