Learning Activity

Exploring Acids and Bases

Subject Area

Science

Grade(s)

9, 10, 11, 12

Overview

How do I know if a substance is an acid or base?  In this activity, the students will use a digital simulation model to explore and gather evidence on how acids and bases dissociate in solution. The students will also gather data on how pH and conductivity change with the strength of an acid or base. Finally, they will develop their own working definition of acid, base, indicator, and pH scale by gathering data during the simulation. This activity is an introductory activity to acids and bases and no prior knowledge is needed to complete the simulation.

Note: The PhET simulation is a free resource that is copyrighted by the University of Colorado. The handout and lesson format are teacher-created. 

This activity was created as a result of the GAP Resource Summit.

Science (2015) Grade(s): 09-12 - Chemistry

SC15.CHM.6

Use mathematics and computational thinking to express the concentrations of solutions quantitatively using molarity.

Unpacked Content

UP:SC15.CHM.6

Vocabulary

  • Molarity
  • Moles
  • Volume
  • Solution
  • Solute
  • Solvent
  • Concentrations
  • Dissolving
  • Solubility
  • Ionic
  • Covalent
  • atomic/ molecular/ particulate level
  • macroscopic level
  • pH
  • hydronium ion
  • hydroxide ion
  • concentration
  • concentrated
  • dilute
  • acids and bases (strong/ weak)
  • properties

Knowledge

Students know:
  • The mole is used to convert between the atomic/ molecular and macroscopic levels.
  • Concentrations of solutions can be compared quantitatively using molarity.
  • Mathematical representations may include calculations, graphs or other pictorial depictions of quantitative information.
  • Solutions are a type of mixture that appears homogeneous at the macroscopic level but may be heterogeneous at the atomic/ molecular level.
  • Solutes are the portion of a solution present in the lesser amount.
  • Solvents are the portion of a solution present in the greater amount.
  • Both temperature and pressure affect the solubility of solutes.
  • The effect of temperature on the solubility of a liquid or solid solute differs from that of gaseous solutes.
  • The effect of pressure on the solubility of gaseous solutes differs from that of liquid or solid solutes.
  • The ability of a substance to conduct electricity is determined by the presence of charged particles that are able to move about freely.
  • Ionic compounds typically conduct electricity when melted or dissolved in water because the charged particles are able to move about freely.
  • Covalent compounds typically do not conduct electricty when melted or dissolved in water because there are no charged particles.
  • Exceptions to the typical conductivity of solutions include strong acids, which ionize in water solutions.
  • An acid has more hydronium ions than hydroxide ions.
  • A base has more hydroxide ions than hydronium ions. pH is a measure of the number of hydronium ions present in a solution.

Skills

Students are able to:
  • Identify solute and solvent in a solution.
  • Calculate the molarity of a solution.
  • Represent the process of dissolving using a model.
  • Analyze data using tools, technologies, and/ or models to identify relationships within the datasets.
  • Use analyzed data as evidence to describe the relationships between temperature changes and pressure changes on solubility.
  • Plan an investigation that outlines the experimental procedure, including safety considerations, how data will be collected, number of trials, experimental setup, and equipment required.
  • Conduct a planned investigation to test the conductivity of common ionic and covalent substances in solution.
  • Analyze collected and recorded data from investigation to determine conductivity of common ionic and covalent substances.
  • Use the pH scale to determine if a substance is acidic or basic.
  • Determine the concentration of hyfronium or hydroxide ions in a solution based on pH value.

Understanding

Students understand that:
  • Mathematical representations of phenomena are used to describe explanations.
  • The properties of matter at the macroscopic level are determined by the interaction of particles at the atomic/ molecular level.
  • Proportional relationships among different types of quantities provide information about the magnitude of properties.
  • Models are used to predict the relationships between systems or components of a system.
  • The properties of matter at the macroscopic level are determined by the interaction of particles at the atomic/ molecular level.
  • Proportional relationships among different types of quantities provide information about the magnitude of properties.
  • Data can be analyzed using tools, technologies, and/ or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims.
  • Different patterns may be observed at each of the scales at which a system is studied and ca provide evidence for causality in explanations of phenomena.
  • The properties of matter at the macroscopic level are determined by the interaction of particles at the atomic/ molecular level.
  • Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
  • Scientists plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design decide on types, how much, and accuracy of data needed to produce reliable measurements.
  • The properties of matter at the macroscopic level are determined by the interaction of particles at the atomic/ molecular level.
  • The function of a material and its macroscopic properties are related to the atomic/ molecular level structure of the material.
  • Models are used to predict the relationships between systems or components of a system.
  • The properties of matter at the macroscopic level are determined by the interaction of particles at the atomic/ molecular level.
  • Proportional relationships among different types of quantities provide information about the magnitude of properties.

Scientific and Engineering Practices

Developing and Using Models; Planning and Carrying out Investigations; Analyzing and Interpreting Data; Using Mathematics and Computational Thinking

Crosscutting Concepts

Patterns; Cause and Effect; Scale, Proportion, and Quantity; Structure and Function
Science (2015) Grade(s): 09-12 - Physical Science

SC15.PS.4

Analyze and interpret data using acid-base indicators (e.g., color-changing markers, pH paper) to distinguish between acids and bases, including comparisons between strong and weak acids and bases.

Unpacked Content

UP:SC15.PS.4

Vocabulary

  • Acid
  • Base
  • Indicator
  • pH
  • Arrhenius theory
  • Strong acid/base
  • Weak acid/base
  • Neutralization
  • Titration

Knowledge

Students know:
  • An acid may be strong or weak, depending on its reaction with water to produce ions.
  • When an acid dissolves in water, a proton (hydrogen ion) is transferred to a water molecule and produces a hydronium ion.
  • A base may be strong or weak, depending on the number of hydroxide ions readily produced in solution.

Skills

Students are able to:
  • Recognize common inorganic acids including hydrochloric (muriatic) acid, sulfuric acid, acetic acid, nitric acid and citric acid.
  • Recognize common bases including sodium bicarbonate, and hydroxides of sodium, potassium, calcium, magnesium, barium and ammonium.
  • Use the pH scale to measure acidity or basicity.

Understanding

Students understand that:
  • Acids are compounds that contain hydrogen and can dissolve in water to release hydrogen ions in solution.
  • Bases are substances that dissolve in water to release hydroxide ions (OH-) into solution.
  • The neutralization of an acid with a base produces water and a salt.

Scientific and Engineering Practices

Analyzing and Interpreting Data

Crosscutting Concepts

Patterns

Phase

During/Explore/Explain
Learning Objectives

Learning Objectives

The students will create definitions supported by evidence for the following terms: acid, base, indicator, pH scale.

The students will compare and contrast strong acids and weak acids using evidence gathered from a digital model.

The students will compare and contrast strong bases and weak bases using evidence gathered by a digital model. 

Activity Details

Explore:

After a starter activity to engage the student, the teacher will introduce the PhET simulation using a projector or interactive smart screen. The teacher should click on items to show the students a basic use of the simulation so that they are not intimidated by learning new concepts using a digital simulation.

Then, the teacher will tell the students that they are going to use a computer simulation to gather data that they will use to describe the scientific concepts of acidity and basicity. The teacher will give the students either a digital or hard copy of the handout. The teacher will explain that the students will work on their own to gather data that they will use to create their own definition of acid, base, indicator, and pH scale. The teacher will explain that each student will have 20 minutes to explore the simulation and answer the questions on their handout. During the activity, the teacher will circulate around the classroom and monitor progress. The teacher should note any misconceptions students demonstrate to redirect their thoughts later during the debrief/class discussion during the explain/elaborate portion of the lesson.

Assessment Strategies

Assessment Strategies

Formative (informal) assessment:

During the simulation, the teacher will use student answers on the handout to gather data on misconceptions to address in the explanation of the lesson at the end of the activity. During the "Think, Pair, Share," the teacher will use student discussion and responses on the poster to note any additional misconceptions that need to be corrected.

Summative (formal) assessment:

The teacher may use the student answers on the handout as a summative grade for the simulation. However, since these answers are discussed in class, a different summative assessment would likely be a more accurate indicator of what individual students know. A suggestion for a final assessment can be found in the variation tips below. 

 

Variation Tips

Since the answers on the handout are discussed in class, the handout is more of a formative assessment to gauge what the students know at the end of the simulation. A summative assessment could be given to each student individually in the form of a quick Quizizz game like the one found here.

For more mature and advanced students in chemistry, the teacher can modify the handout to make the questions and exploration more rigorous. The teacher can introduce additional terms to the students like hydronium ion, hydroxide ion, neutral, etc.

This activity is meant to introduce the concept of acids and bases to students. An acids and bases lab would be an excellent follow-up activity to allow students to use the skills that they learned in the simulation to actually test the pH of different substances in the lab and classify the substances as acids or bases. 

Background and Preparation

Background / Preparation

The teacher will need to ensure that students have access to a computer with internet access before the lesson. Since the simulation is an HTML simulation, it will work on Chromebooks as well as other laptops in the web browser. Always test websites before you attempt to use them in class in case they are blocked by your school filter. 

The teacher should also complete the simulation so that they are familiar with the operation and capable of helping students when they are "stuck." 

The teacher should also make copies of the handout, if necessary. 

Digital Tools / Resources

Acids-Base Solutions PhET Interactive Simulation
https://phet.colorado.edu/en/simulation/acid-base-solutions

Approved Date

Owner (Author)

kmcgrady
ALSDE LOGO

This site may contain links to other websites or content belonging to or originating from third parties or links to websites and features in banners or other advertising. Such external links are not investigated, monitored, or checked for accuracy, adequacy, validity, reliability, availability, or completeness by us. WE DO NOT WARRANT, ENDORSE, GUARANTEE, OR ASSUME RESPONSIBILITY FOR THE ACCURACY OR RELIABILITY OF ANY INFORMATION OFFERED BY THIRD-PARTY WEBSITES LINKED THROUGH THIS SITE.
Alabama Learning Exchange © 2002-2023 by Alabama State Department of Education is licensed under Attribution-NonCommercial-ShareAlike 4.0 International

Design by Adaptive Theme