Acids and Bases in Chemistry

Grade Level/Course Code: Grade 10 Applied Science (SNC2P1)

Strand(s) and Unit(s): Chemistry: Chemical Reactions and Their Practical Applications

Overview: Students will investigate chemical reactions and their uses through a series of inquiry based activities where they will develop their understanding of acids and bases and how they react.

Inquiry Focus:

                Key Terminology: Chemical Reaction, Reactants, Products, Word Equation, Acid, Base, pH

                Key Questions: What is an Acid? What is a Base? How do Acids/Bases react?

Timeline:

Day 01 – Introduction with the Use of Water

Day 02 – Properties of Acids

Day 03 – Properties of Bases

Day 04 – Making Indicator Paper (This requires the indicator paper made to dry overnight. Depending on humidity and temperature of the school, this could take longer. It is recommended for ideal results to let the papers dry over the weekend)

Day 05 – pH

Day 06 – Calibrating Indicator Paper

Day 07 – Indicators

Day 08 – Household pH

Day 09 – Naming Acids and Bases

Day 10 – Neutralization

Day 11 – Comparing Antacids

Day 12 – Acid Rain

Big Ideas:

  • Chemicals react with one another in predictable ways.
  • Chemical reactions are a necessary component of chemical products and processes used in the home and workplace.

 

 

Overall Expectations:

 

C2. -  investigate, through inquiry, the characteristics of simple chemical reactions;

C3.  - demonstrate an understanding of simple chemical reactions and the language and ways to represent them.

 

Specific Expectations

C2.1 use appropriate terminology related to chemical reactions

C2.2 construct molecular models of simple chemical reactions

C2.3 conduct and observe inquiries related to simple chemical reactions, and represent them using a variety of formats

C2.4 use an inquiry process to investigate the law of conservation of mass in a chemical reaction and account for any discrepancies

C2.5 use an inquiry process to investigate acid–base neutralization reactions

C2.6 conduct an inquiry to classify some common substances as acidic, basic, or neutral

C2.7 investigate applications of acid–base reactions in common products and processes

C3.2 name and write the formulae for simple ionic and molecular

C3.3 write word equations and balanced chemical equations for simple chemical reactions

C3.4 describe the process of neutralization for simple acid–base reactions

C3.5 describe how the pH scale is used to identify the concentration of acids and bases

 

Key Concepts:

Acids and Bases and how they react.

Prior Skill Sets:

  • Basic lab skills and safety
  • Ability to follow directions both written and verbal
  • Basic graphing ability
  • Ability to make correct measurements (example understanding meniscus)

Prior Knowledge:

  • Understanding of the atom
  • Understanding of elements
  • Understanding of how/why elements react

Materials and Equipment:

Day 01 – Clean beakers (3 per group), hot plate, distilled water, salt water, and electronic balance

Day 02 – Blue Litmus Paper, Red Litmus Paper, Phenolthalein, Magnesium, test tubes, 0.1 M HCl, Vinegar, droppers

Day 03 – Blue Litmus Paper, Red Litmus Paper, Phenolthalein, Magnesium, test tubes, 0.1 M NaOH, 0.1 M Mg(OH)2, droppers

Day 04 – 1 L beaker, scissors (scalps can be used depending on the students), 500 mL beaker, Strainer, Filter Paper (coffee filters work very well)

Day 05

Day 06 – pH paper, 1 strong acid, 1 weak acid, 1 strong base, 1 weak base, 1 neutral solution, droppers, 50 mL beaker, 150 mL Erlenmeyer Flask, homemade indicator paper, homemade indicator solution

Day 07 – Spot plate, homemade indicator paper, homemade indicator solution, droppers, 9 commercial indicators, 0.1 M HCl, 0.1M NaOH, Distilled water

Day 08 – Spot plate, droppers, pH paper, 15-20 common household products (foods, cleaning products, soaps, etc)

Day 09

Day 10 – droppers, universal solution, 250 mL beakers, 0.05 M Acetic Acid, 0.1 M HCl, 0.01 M NaOH

Day 11 – 600 mL 0.1 M HCl, 250 mL beaker x 6, universal solution, 6 over the counter antacids, 6 stop watches

Day 12

Safety:

  • Wear goggles while performing lab experiments
  • Understand correct use and supervision of heat sources
  • Correct usage and handling of acids – consult MSDS
  • Correct usage and handling of bases – consult MSDS
  • Correct usage and handling of indicators – consult MSDS
  • Proper disposal of acids, bases, indicators and metals, this varies from region to region and depends upon what facilities and equipment are available to the teacher.

Instructional Planning and Delivery:

Day 01 – Introduction with the Use of Water

                Students will compare different types of water by boiling them. Students will examine the structure of water and its natural decomposition. Based on the products from the natural decomposition students will start to develop the ideas of acids, bases and neutral solutions. Then extend these ideas in order to explain why water is considered the universal solvent.

Day 02 – Properties of Acids

                Students will perform a series of experiments on two common acids in order to determine the properties of acids.

Day 03 – Properties of Bases

                Students will perform a series of experiments (very similar to those of the acids) in order to determine the properties of bases in order to develop the ability to compare acids and bases.

Day 04 – Making Indicator Paper

(This requires the indicator paper made to dry overnight. Depending on humidity and temperature of the school, this could take longer. It is recommended for ideal results to let the papers dry over the weekend.)

                Students will make their own indicator paper by chopping up colored vegetation and boiling it. Filter paper will then be soaked in the boiling solution in order to pick up the dyes. The paper and the solution will then be stored for future use.

Day 05 – pH

                Students will learn the extreme basics about pH and the patterns of calculation based off the logarithmic calculation of the concentration. Students will complete basic questions based on the patterns and complete a graphing activity in order to reinforce the power of 10 relationship.

Day 06 – Calibrating Indicator Paper

                Students will use different solutions and determine the how their homemade indicators react to different acids and bases.

Day 07 – Indicators

                Students will examine a wide variety of different indicators and how they generally react to acids and bases. Students will then be asked to hypothesize why so many different indicators exist and what each could be used for.

Day 08 – Household pH – See Science 10 page 300

Day 09 – Naming Acids and Bases

                Students will examine the basic naming rules for acids and bases.

Day 10 – Neutralization

                Students will perform a very crude titration reaction in order to develop a basic understanding of neutralization reactions. Students will add small amounts of a base to different acids to show that neutralization reacts are slow and require specific amounts based upon the concentration of the acid and not the volume.

Day 11 – Comparing Antacids – See Science 10 page 320

Day 12 – Acid Precipitation

                Students will examine a PowerPoint in order to develop an understanding of how acid precipitation is formed and the damage that the formation process causes.

Student Support Resources:  

See Attachments

 

Related Background Resources and/or Links:

Ritter, B., Plumb, D., & Jenkins, F. (2001). Nelson Science 10. Scarborough, Ont.: Nelson Thomson Learning.

Assessment Opportunities:

For Learning: Students’ level of participation and understanding of terminology and concepts can be determined on an ongoing basis throughout the unit by teacher observation and questioning. The teacher can also choose to take up or look at written answers to each day’s activity in order to track the progress of the individual students.

As Learning: Self- and peer-assessment opportunities include collaboration during the investigations and discussion in regards to the completion of the day’s written answers to the associated questions. 

Of Learning: Many different aspects of the unit can be turned into summative assessments. The Comparing Antacids and the Household pH tend to be the most comprehensive. Students also perform very well when the Naming of Acids and Bases and the Indicator Lab are formally assessed.

Future Opportunities / Extensions:

This allows students to develop the background information to conduct further research into the uses of acids and bases for such things as food preservation or for farming purposes.

Many different industrial personal could be arranged as guest speakers who employ the use of acids in their jobs.

MNR personal could be contacted to extend the effects of Acid Rain and the recovery efforts.

 

READ MORE