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Research & Teaching

Connecting pH and Molarity to Health Care

A Qualitative Assessment of BSN Student Responses to an Online Lab Exercise

Journal of College Science Teaching—November/December 2022 (Volume 52, Issue 2)

By Angela L. Mahaffey

Given the recent state of social distancing, the online lab experience discussed in this article offers an economical and versatile approach to online undergraduate chemistry lab instruction. With videoconferencing software, this experience is easily adaptable to a socially distanced learning environment, although it was initially designed for a classroom (nonlaboratory) setting with an instructor present. The chemistry for health professions lab course described was designed with electronic prelab testing, postlab testing, and lab report submission via an online learning management system for each of the nearly dozen online lab exercises. This article assesses qualitative student responses to the online Urinalysis, pH, and Molarity virtual lab exercise offered in this lab course for health sciences majors. Students anonymously surveyed in the fall 2019 semester course (n = 161) noted the “student-friendly” and cognitively promoting characteristic of the online lab experience. The virtual workbench and online pre- and postlab testing and lab report submission (with data sets) provided an immersive chemical laboratory experience for the students enrolled, and more than 90% of the 138 fall 2019 semester students noted that they would recommend this lab experience to future undergraduate health sciences students enrolled in the Chemistry for Health Professions lab course.


Social distancing is gradually defining the new norm for undergraduate education and limiting course practicum, such as empirical laboratory studies. The need for integrating virtual or simulated learning practica into undergraduate physical and health sciences courses is becoming more apparent. This article shares an evaluation of undergraduate health professions nursing (bachelor of science in nursing [BSN]) and exercise sciences (bachelor of science in exercise sciences [BSES]) students’ responses to a completely online chemistry lab experience—Urinalysis, Molarity, and pH—which mirrors an on-campus undergraduate chemistry education lab protocols. Since 2017, a School of Nursing Chemistry for Health Professions face-to-face but virtual lab course was created and is fully operational. To clarify, the lab course is structured in a manner that allows BSN/BSES students to complete the 2D virtual lab (using a laptop, tablet, or iPad) in the presence of a lab instructor and other student participants. By fall 2021, more than 880 undergraduate health sciences enrollees participated in the face-to-face online Chemistry for Health Professions lab course, with a passing rate of over 95% (for fall semesters 2017–21). It is important to note that in the present era of social distancing, an easy update of having the lab instructor facilitate the lab and office hours via videoconferencing can be implemented in place of a classroom setting. The design of the course offered weekly practical chemistry lab experimentations, using a coordinated effort on the Sakai learning management system (LMS; Sakai, 2022) and online supplemental chemistry platforms (Yaron et al., 2010). As an effort to offer a broader lab experience, students are assigned a prelab assignment, online virtual lab experimentation, postlab assignment, and lab report (submitted electronically).

Urinalysis and pH indicators

Urinalysis is the fluid analysis of a patient’s urinary samples, and it uses a myriad of chemical reactions, including acid-base chemistry and indicators such as methyl red (detection of acids) and bromothymol blue (detection of bases; Mundt & Shanahan, 2011; Strasinger & Di Lorenzo, 2014). Medical conditions such as metabolic, respiratory, or even diabetic (keto) acidosis (Batlle et al., 2017; Cecere et al., 2013; Chiasson et al., 2003; Mayo Clinic Staff, 2020; McMahon, 2017; Sakai et al., 2016; Westerberg, 2013) and plasma alkalosis disorders result in symptoms identified through urine sample diagnostics. In a class of undergraduate health professions (nonchemistry) majors, an opportunity was presented to overlap the science of chemical acid-base analysis and health care diagnostics using a virtual lab platform. One empirical motif shared by both chemistry practical pH labs and medical diagnostics (such as urinalysis) is colorimetry, a visual indication of a marked increase or decrease in moles of hydrogen ions (H+) or hydroxide ions (OH-) present in an aqueous sample. This measurement is made apparent by a spectrum of colors, often promoted by the oxidation or reduction of an indicator molecule (e.g., methyl red; Figure 1). By doing the virtual lab exercise described in the article, students examined four additional acid-base indicators—bromocresol green (Batlle et al., 2017; Cecere et al., 2013; Chiasson et al., 2003; Mayo Clinic Staff, 2020; McMahon, 2017; Sakai et al., 2016; Westerberg, 2013), methyl orange (Aziztyana et al., 2019), methyl red (Aziztyana et al., 2019), and phenolphthalein (Wittke, 1983)—in strong acid (HCl, HNO3, and H2SO4) and weak acid (CH3COOH and H3PO4) solutions. pH ranges were identified using the Sigma-Aldrich database (Figure 1).

Figure 1
Reactions of the pH indicators used in the online lab assignment.

Reactions of the pH indicators used in the online lab assignment.

Health sciences students were able to identify the resulting colorimetry of acid-base indicators and the pH of strong and weak acid solutions. This online lab was complemented with an economic, student-friendly, and environment-friendly mock urinalysis demonstration (Mahaffey, 2020b) in which acid-base, pH, and redox reactions and colorimetry mechanisms were highlighted.

Pedagogical objectives

The overall goal of this lab was to highlight chemistry concepts in health care diagnostics and medical examinations. The lab lasted 1 hour and 55 minutes, which included a prelab lecture. The objectives (as complemented by a mock urinalysis demonstration) were as follows:

  • Introduce nursing (and exercise sciences) students to pH, molarity, and dilution concepts as they pertain to health care and urinalysis.
  • Allow students to identify and define the concepts of pH and molarity.
  • Help students understand how pH analysis is applicable to health care (e.g., urine, blood, and saliva analysis).
  • Enable students to analyze the molarity and pH of given samples using the online virtual lab module.

Previous assignments for the didactic Chemistry for Health Professions course underlined the presence of general, organic, biological, and analytical (GOB-A) chemistry in published medical cases (Mahaffey, 2019b). Another lab exercise utilized two-dimensional (2D) molecular-drawing software to help nursing and exercise science students visualize pharmaceuticals and neurobiological molecular structures, which allowed them to make connections between organic and biological chemistry, molecular structure and functions, and health care themes (Mahaffey, 2019a). These assignments prepared students for themes of the subsequent BSN and BSES curricular course, Human Physiology. For the lab presented in this article, connections were made between a practical pH chemistry lab and the utility of such approaches in urine strip analysis for patient pH levels. Primarily, students were introduced to pH, concentration and molarity [H+]/[OH-], and colorimetry via this online platform. The visualizations of the acid-base reactions (in the “virtual workbench” for the Chemcollective module) allowed students to observe the changes in the virtual acid or base solutions. Colorimetry aided in the pedagogical approaches for instructing students on changes in pH, molarity, and concentrations ([H+] or [OH-]) in acid and base solutions. This virtual foundation allowed students to make connections to health care in the lab practicum (Figure 2), as concepts overlapped with lectures on metabolic acidosis and alkalosis and how the renal and urinary systems maintain a homeostasis in blood plasma pH (7.35–7.45) by filtering and reabsorbing H+ or HCO3- (bicarbonate) ions when necessary. This chemistry–health care connection was further elucidated in the lab report discussion question, for which students had to transcribe their comments and the comment of a partner in response to the following prompt: “Now that you have completed the Urinalysis, pH, and Molarity lab assignment, please consider the following discussion topic: Considering blood analysis labs, what are some diseases identified by low blood pH results?” (See Qualitative Student Responses section for the comments.)

Figure 2
Figure 2 Making connections between the “wet lab” and virtual lab acid-base chemistry concepts and health care diagnostics such as urinalysis.

Making connections between the “wet lab” and virtual lab acid-base chemistry concepts and health care diagnostics such as urinalysis.

Experimental procedures

The Urinalysis, pH, and Molarity experiment was originally designed as part of a virtual, face-to-face (see Figure 3) Chemistry for Health Professions lab course during the fall 2017 through fall 2019 semesters (with remote learning fall 2020, and returning to face-to-face fall 2021; Mahaffey, 2022). As noted earlier, in the current paradigm of social distancing, an easy update of having the lab instructor facilitate lab class and office hours via videoconferencing can be implemented in place of a classroom setting. The prelab folder was made accessible in the Resources section of Sakai LMS. Students had up to 1 week to review prelab resources, which often included images and a PowerPoint presentation. During this prelab period, students were also assigned a prelab quiz in Sakai LMS Tests & Quizzes page. Prior to the semester, a classroom (not laboratory) was assigned by the university’s Office of Registration for the virtual lab setting. The lab began with a more detailed prelab lecture presentation by the lab instructor, after which students began the online virtual lab exercises (on tablets, iPads, MacBooks, or laptops). Students selected the Strong Acids and Bases module from the Chemcollective site and followed the instructions adapted specifically for the course (see the Online Appendix to download the sample prelab questions, postlab questions, and lab protocols). Students were allowed to work separately or in pairs, preferably using the Chrome internet browser previously installed on their laptops, tablets, or iPads. Following completion of the virtual lab exercise, in which students were instructed to record pertinent data sets, students completed a postlab quiz in the Sakai LMS Tests & Quizzes section and a lab report in the Assignments page (Figure 3).

Figure 3
Online formatting for virtual lab experience.

Online formatting for virtual lab experience.

Table 1. Pre- and postlab assessment data and student pass and no pass percentages per fall semester (2017–19).a

Fall 2017

Fall 2018

Fall 2019

Students (N)




Lab sections




Average ± SD for postlab scores

(20 possible points for assignment)

16.75 ± 1.19

17.31 ± 0.74

17.00 ± 0

Chemistry for Health Professions lab course

pass percentageb




Chemistry for Health Professions lab course

withdraw/no pass percentageb




a. The Chemistry for Health Professions lab course is offered during fall semester.

b. Data for course pass rates were provided by Loyola University’s Office of Institutional Effectiveness.

Results and discussion

Urinalysis, pH, and Molarity lab assessment results

The average postlab scores for the lab were around 85% (17/20) for the fall 2017 through fall 2019 semesters. As this lab helped introduce the pH topic for first-year undergraduate health sciences students enrolled in the chemistry lab course, the average was laudable for the student body. A recent publication noted a poll for a similar undergraduate, nonmajors demographic enrolled in a previous year’s course in which more than 60% of the student body said that the last chemistry class in which they participated was during their sophomore year of high school (Mahaffey, 2020a) or more than 2 years prior to this chemistry pH lab. As such, the familiarity gained from completion of this lab bodes well for student learning. The lab was one in a series of online, face-to-face chemistry lab exercises offered in this course for 3 years (Table 1). An up-to-date comparison of pass/fail rates for the face-to-face Chemistry for Health Professions lab courses (with virtual lab offerings) from the fall semesters between 2017 and 2021 with the 2015–2016 semesters of the parent “wet lab” course is available in a recently published article (Mahaffey, 2022). The Chemistry for Health Professions lab course is only offered during the fall semester in the School of Nursing; this course combines GOB I and II concepts for health professions students. Students experienced a full undergraduate lab, inclusive of pre- and postlab assignments, lab reports with data sets, and virtual lab workbench, with a successful passing rate over 94% for fall semesters between 2017 and 2019.

Qualitative student responses

During the fall 2019 semester, undergraduate health sciences enrollees were asked to complete an anonymous and voluntary survey (see example in Figure 4) regarding the lab and their experiences. This survey was designed to gauge the student-friendly aspects of the lab, as well as students’ attitudinal and cognitive perceptions of the lab design, the online platforms (LMS and virtual lab applications), and the exercise.

Figure 4

Sample postlab survey.

Q1: The prelab Sakai Resource folder was helpful for this lab.

A. strongly agree

B. agree

C. n/a (not applicable)

D. disagree

E. strongly disagree

Q2: The virtual lab exercise for this
lab was ...

A. easy to use

B. moderately easy to use

C. neither

D. slightly difficult to use

E. difficult to use

Q3: The online (Sakai LMS) postlab questions were reasonable in relation
to the lab topics.

A. strongly agree

B. agree

C. neither agree nor disagree

D. disagree

E. strongly disagree

Q4: The laboratory exercise increased my knowledge of chemistry.

A. agree

B. somewhat agree

C. neither agree nor disagree

D. somewhat disagree

E. disagree

Q5: The lab report writing (and electronic submission) format increased my knowledge of scientific writing, as a future health professional.

A. agree

B. somewhat agree

C. neither agree nor disagree

D. somewhat disagree

E. disagree

Q6: The lab discussion question(s) helped me see the correlation between the lab and healthcare.

A. agree

B. somewhat agree

C. neither agree nor disagree

D. somewhat disagree

E. disagree

Q7: As a student, you would recommend the lab assignment to be utilized in future undergraduate Chemistry for Health Professions lab courses.

A. agree

B. somewhat agree

C. neither agree nor disagree

D. somewhat disagree

E. disagree

The results of the anonymous student survey (Figure 5), completed by 138 of the 161 students enrolled in the lab course, provide a few key observations on the following topics: (i) student interest in the lab resources posted in the Sakai LMS; (ii) the online pH lab module; (iii) the online pre- and postlab quizzes (see the Online Appendix to download the prelab and postlab activities and lab protocols); (iv) electronic submission of a lab report (an important process for undergraduate health professions students, given the current practices of electronically submitting medical records and patient care reports; Health Information & Technology Committee of NHLA/AAHA, 1997); (v) the chemistry–health care connections garnered through the assigned lab report’s discussion question; and (vi) student recommendations for the online lab (LMS and virtual lab module) processes for future Chemistry for Health Professions lab courses. Here is a sampling of the findings:

Figure 5
Figure 5 Graphical analysis of anonymous and voluntary student survey results.

Graphical analysis of anonymous and voluntary student survey results.

  • 93% agreed that the online prelab Resource folder was helpful.
  • 86% noted that the virtual lab module was easy to use.
  • 96% agreed that “the online postlab questions were reasonable in relation to the lab topics.”
  • 94% agreed the lab exercise increased their knowledge of chemistry.
  • 91% were in favor of the assigned electronic lab report submission being offered to future students.
  • 94% agreed that the “discussion question helped [them] to see the correlation between the chemistry lab and health care.”

Additionally, the following anonymous student comments note a student-friendly characteristic of this online chemistry lab exercise:

  • “I believe that this lab was the easiest and most beneficial to the students in the nursing program because there was a very clear correlation between the material being done in the lab and how it is used in the field of health care. Also, it was beneficial to the students because it was very easy to use; therefore we had time to understand the principles behind the work.”
  • “I thought the lab itself had an interesting concept with many connections to the health care field, so I enjoyed learning about that.”
  • “This lab was the most user-friendly lab … and the chart in the prelab was easy to read and made for efficient experimenting and lab report writing.”
  • “This lab was very informational and helped me grasp a well-rounded view of pH.”
  • “I really liked this lab, I enjoy the discussion questions and how they tie into health care. It reassures us as students that what we are learning in chemistry ties into nursing.”
  • “I think the urinalysis lab was very helpful. I was able to learn the importance of knowing a patient’s pH levels. It also taught me how acid-base reactions react with one another and why the pH levels change.”
  • “I think this lab was my favorite of them all so far this year. Urinalyses are commonly utilized in health care for diagnostics, so this lab helped me to gain knowledge in this topic.”
  • “This lab was helpful in learning more about pH and how this can be seen in the health care world. The correlation of levels of acid and bases in tests from the body helped see this connection clearly.”
  • “It was very interesting looking at the color change of the solutions. [The] lab was easy to operate and honestly was a great experience.”
  • “This lab was very beneficial because it allowed me to understand what pH can reveal in a patient’s body. I liked how the prelab introduced the ideas of pH and pH indicators being used in the health care field and how acidic and alkaline a substance can be.”


This article presents a viable, fully comprehensible online approach to a chemical education lab experience for undergraduate health sciences majors. The online chemistry lab environment and LMS outlined in this article are currently free and accessible to students who have a computer and are registered in a course using any applicable LMS (e.g., Sakai). This lab protocol provides an immersive learning experience in which students are capable of visualizing (using pH indicators as colorimetric standards) changes in concentrations of hydrogen and hydroxide ions in acid or base solutions, then connecting these underlined themes in health care biofluid diagnostics (such as pH analysis of patient urine samples) in the electronic lab report discussion question.


Health sciences curricula identify the important role of practical chemistry education (e.g., chemistry lab courses). However, during the era of social distancing, many instructors have found it challenging to design a successful practical chemistry experience. In the case of distance learning, the recommendation is that the lab and supplemental descriptions provided in this article, in conjunction with online videoconferencing and submission of student work via LMS (in lieu of a face-to-face setting), offer one viable alternative to hands-on chemical practicum usually presented in a physical laboratory setting (Mahaffey, 2022). The qualitative student responses noted in this article show that this approach is both student friendly and educational.


I would like to acknowledge the student participants.

Angela L. Mahaffey ( is an assistant professor in the Marcella Niehoff School of Nursing at Loyola University Chicago.


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Assessment Chemistry Distance Learning Instructional Materials Interdisciplinary College

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