Acids and Bases Information Page

Broad definition of what we are considering

We primarily considered videos that focused on the conceptual understanding of why compounds act as an acid or a base. We considered both Bronstead-Lowry and Lewis Acids and Bases.

We did not code videos that just provided a definition of an acid (e.g., a proton donor) (and/or base) and gave examples of acids or bases using that definition to identify an acid. We DID code the video if they provided the definition and used that definition to identify examples AND it also includes something additional, e.g., looks at structural features of the example compounds that correspond to acid behavior.

Johnstone's Triangle Elements

Acid and Bases Specific Criteria

Element	Examples
Macroscopic	Showing that a solution is acidic or basic using a pH meter or pH paper. Examples of common things (lemon juice, vinegar, baking soda) that are acids or bases including talking about taste. Examples of acids and bases reacting (e.g., vinegar and baking soda). Pouring an acid into water.
Symbolic	Chemical equations showing acids as proton donors and bases as proton acceptors. Lewis structures of single acid molecules showing acidic H, resonance stabilization of conjugate base, arrows showing inductive effect. Ka expression equations. An electron pushing mechanism is symbolic not particulate.
Particulate	Particle diagrams illustrating what happens when acids or bases dissolve in water, what happens when they react. Just having a particle drawing in an equation does not count. Must somehow show HOW the particles interact for acids/bases dissolving in water or reacting. Bohr model to show relative size of ions related to stability. NOT just larger or smaller circles unless they talk about size of electron cloud/number of electrons related to size of the circle.
Connection between levels	Videos should make explicit connections between two or more levels for this to be coded as present. For example, they could show the chemical reaction along with a particle level drawing or animation.

Core Ideas

Change and Stability in Chemical Systems	Atomic/Molecular Structure & Properties	Electrostatic Bonding and Interactions
Core Ideas Elements
Energy and entropy changes, the rates of competing processes, and the balance between opposing forces govern the fate of chemical systems.	The macroscopic physical and chemical properties of a substance are determined by the three‐dimensional structure, the distribution of electron density, and the nature and extent of noncovalent interactions between the particles.	Attractive and repulsive electrostatic forces govern noncovalent and bonding (covalent and ionic) interactions between atoms and molecules. The strength of these forces depends on the magnitude of the charges involved and the distances between them.
Video needs to include: Discussion of why acids dissociate in water (reacting with water and donating a proton) or why it reacts with a base. Must explicitly mention stability. This may focus on the relative stability of the conjugate base of an acid, without in-depth discussion about the structural features which lead to that stability.	Video needs to include: Discussion of how the structural features of a molecule impact its relative strength as an acid or base (will usually need to compare multiple acids or bases) e.g. a more stable conjugate base will be linked to a stronger acid.	Video needs to include: Discussion of acid-base reactions in terms of electrostatics/polarity (e.g., positive/slightly positive end of one species reacts with the negative/slightly negative end of another species).

Casual Mechanistic Reasoning

Must have both How and Why?

Option 1: What causes acids to react?

How: Acids react, generally by donating H⁺ ions, to form products that are more stable. OR The more stable the anion formed when an acid dissociates in water, the greater the amount of dissociation and stronger the acid. Must mention stability.

Why: Acidic H atoms are generally bonded to highly electronegative atoms (O or halogens). In donating the acidic H ion to another species more stable products are formed, generally a stable anion and in the case of acid dissolving in water, H₃O⁺. The more stable the products, the more product favored the equilibrium system will be. Does not need to explicitly address equilibrium.

Option 2: What makes a substance more or less acidic? (Assuming we will see this for Bronstead-Lowry acids)

How: Molecules with polar H-X bonds and that form stable conjugate base (anions) when dissociated are stronger acids.

Why: Anions that can delocalize the negative charge by having the negative charge on larger electronegative atoms (e.g., Cl^–) or on anions that are stabilized by inductive effects or resonance are more stable. (Note: A more stable conjugate base will make the process of losing an H⁺ less energetically unfavorable – videos are not required to have this piece, but please note if the video does explicitly include the energy piece.)

Scientific Practices

Most Frequent Science Practices
SP 2: Developing and Using Models Instruction presents an event, observation, or phenomenon for instructor/students to explain or make a prediction about. Instruction presents a representation or asks instructor/students to construct a representation. Instruction has instructor/students explain or make a prediction about the event, observation, or phenomenon. Instruction has instructor/students provide the reasoning that links the representation to their explanation or prediction.
SP 4: Analyzing and Interpreting Data Instruction presents a scientific question, claim, or hypothesis to be investigated. Instruction provides a representation of data (table, graph, or list of observations) used to answer the question or test the claim or hypothesis. Instruction provides an analysis of the data or asks instructor/students to analyze the data. Instruction has instructor/students interpret the results or assess the validity of the conclusions in the context of the scientific question, claim, or hypothesis.
SP 5: Using Mathematics and Computational Thinking Instruction presents an event, observation, or phenomenon. Instruction has instructor/students perform a calculation or statistical test, generate a mathematical representation, or demonstrate a relationship between parameters. Instruction has instructor/students give a consequence or an interpretation in words, diagrams, symbols, or graphs of their mathematical results while demonstrating reasoning in the context of the given event, observation, or phenomenon.
SP 6: Constructing Explanations and Engaging in Argument from Evidence Instruction presents an event, observation, or phenomenon. Instruction presents or asks instructor/students to make a claim based on the given event, observation, or phenomenon. Instruction has instructor/students provide scientific principles or evidence (data or observations) to support the claim. Instruction has instructor/students provide reasoning about why the scientific principles or evidence support the claim.

Multimedia Principles

Multimedia learning as knowledge construction: The goal of multimedia presentations is not only to present information but also to provide guidance for how to process the presented information – that is, for determining what to pay attention to, how to mentally organize it, and how to relate it to prior knowledge. We will categorize the videos along each of the following criteria (High and Low should be mutually exclusive.)

High	Low
Video almost exclusively involves meaningful and relevant images and verbal components AND images are explained for a novice learner Text on screen is minimal (ex. Only brief bullet points or keywords or definitions if text is used) Content is all relevant to the topic and learning (no music, unhelpful animations, graphics, etc.) Contains elements that meaningfully support student organizing content or identify key ideas (introductory organizer, section heading, summary, guiding questions/topic (for short, focused video only) Key Question: Could a novice learner clearly understand what they should take away from the video? Yes=high.	Large segments of video are presented just verbally and not pictorially (ex. just the instructor talking, or just written words) OR images presented are not relevant to learning or explained Contains full sentences of written text that are also narrated (e.g., several bullet points or sentences on one screen OR full sentences of text on many screens includes forced closed captioning) Contains extraneous content, music, graphics, animations, background changes, sounds, or just too much stuff on the screen at one time - anything that detracts attention from core content Does not contain any elements that meaningfully help learners organize content or identify key ideas (e.g., no introductory organizer, section headings, video segments, summary, guiding question/topic (for short focused videos only)

High

Low

Video almost exclusively involves meaningful
and relevant images and verbal components
AND images are explained for a novice
learner
Text on screen is minimal (ex. Only brief
bullet points or keywords or definitions if text
is used)
Content is all relevant to the topic and learning
(no music, unhelpful animations, graphics,
etc.)
Contains elements that meaningfully support
student organizing content or identify key
ideas (introductory organizer, section heading,
summary, guiding questions/topic (for short,
focused video only) Key Question: Could a
novice learner clearly understand what they
should take away from the video? Yes=high.

Large segments of video are presented just
verbally and not pictorially (ex. just the
instructor talking, or just written words) OR
images presented are not relevant to learning
or explained
Contains full sentences of written text that are
also narrated (e.g., several bullet points or
sentences on one screen OR full sentences of
text on many screens includes forced closed
captioning)
Contains extraneous content, music, graphics,
animations, background changes, sounds, or
just too much stuff on the screen at one time -
anything that detracts attention from core
content
Does not contain any elements that
meaningfully help learners organize content or
identify key ideas (e.g., no introductory
organizer, section headings, video segments,
summary, guiding question/topic (for short
focused videos only)

Misleading vs. Inaccuracies

Several minor spelling issues is misleading, not inaccurate

Example High Quality Videos

Examplar Videos

These are examples of videos that were found to provide good illustrations of some or many of the framework components for this concept. Develop a deep understanding of chemistry concepts requires multiple experiences with the material and these videos may provide one such experience.

Exemplar Video 1	Exemplar Video 2	Exemplar Video 3
Comments This video provides a good overview of the inductive effect with respect to acid strength. It first explains induction and then talks about the importance of electronegativity and distance. It ends with a comparison of the relative strengths of Ethanoic acid and Benzoic acid using inductive effect to explain the differences.	Comments This video provided a strong overview on a lot of AB topics. He started with definitions for the first 3 minutes, then moved into talking about acids and their conjugates. Described how a conjugate base can be stabilized. He then explained pKa followed by pH/pOH.	Comments This video explains the effect of resonance on acid strength and compares ethanol with acetic acid. It evaluates the charge of both (-1) and atom carrying charge (both O). It then analyzes whether the atom holding the charge can form a resonance structure to delocalize the negative charge.
Strengths This video had strong multimedia principles and met the criteria for both CI and CMR. Our team rated this as "very helpful" because it was easy to determine what we should take away from the video.	Strengths This video contained a self-assessment portion for students from 8:00–8:30. The explanations were thorough and easy to follow; he also provided helpful equations to explain the concentration of acids and bases.	Strengths This video contains strong multimedia principles. It takes a very specific topic and dives thoroughly into why certain compounds are stronger or weaker acids.
Weaknesses This video did not contain macroscopic or particulate representations. It also contained misleading parts by personifying atoms.	Weaknesses This video did not contain macroscopic or particulate representations. It also contained misleading parts.	Weaknesses This video did not contain macroscopic or particulate representations of atoms.

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