General Chemistry courses are often challenging for first-year college students preparing for science, technology, engineering, and mathematics (STEM) programs. These courses are among the STEM gateway courses in which many students struggle to get through, or are weeded out. This is partly due to the use of ineffective study strategies such as rote memorization. To prepare these students for STEM trajectories, metacognitive strategies should be taught early. Unfortunately, limited research has been conducted on the impact of metacognition instruction on students' learning outcomes at college level. To address this gap, two metacognition-related interventions were conducted with General Chemistry I course students at Oklahoma State University. The first intervention assessed the impact of metacognition instruction on students' study strategies and performance in the final cumulative exam in the Spring of 2019. Additionally, the study investigated the impact of the instruction on different demographic groups and whether the learned metacognitive strategies were transferred to other STEM courses. Open-ended questionnaires were used. Findings showed a reported dominant use of lower-order study strategies (LOSSs), such as rote memorization over higher-order study strategies (HOSSs) before the metacognition instruction. However, more gains in HOSSs were reported after the metacognition intervention. Additionally, 67% of students reported a positive influence of the metacognition instruction on study strategies with 7% lower DF letter grades in the final exam compared to their counterparts who reported 'no influence'. Findings also showed evidence of equity gaps in the reported use of specific study strategies based on gender, race/ethnicity, and first-generation status prior to the metacognition instruction. However, these gaps were narrowed or closed with students' exposure to the study strategies. Additionally, participants from all the demographic groups reported transfer of the acquired study strategies to other courses. The second study investigated the effects of muddiest point activities, a reinforced metacognition regulation skill, blended with the common formative assessments (FAs) on performance as well as on student learning experiences during Fall 2019. Using a quasi-experimental research design, one group of students (treatment group) was exposed to the muddiest point activities experiments at the end of each chapter combined with common FAs, and another group (comparison group) to the common FAs alone. Results showed that the treatment group performed significantly better in all three in-term chemistry tests and slightly better in the final cumulative exam, but the difference was not statistically significant (p < 0.05) than the comparison group. Additionally, minority, minority-first-generation, and female-first-generation students in the treatment group scored higher mean scores on some midterm exams, compared to their peers in the comparison group. Also, muddiest point activities were reported to improve students' abilities to identify and address gaps in knowledge, decrease anxiety in the course, increase persistence, and increase confidence in the course. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]