This thesis reports on a study that examined the impact of implementing SWH (inquiry-based approach) in a general chemistry lab on non-science-major students' understanding of chemistry concepts and students' perceptions toward writing in science and implementing SWH. This study was conducted in a large university in the Midwest of the United States in a college freshman chemistry laboratory for non-science-major students. The research framework is presented including the following: the qualitative research design with the observation as data collection method for this design and the criteria for teacher level of implementation and the ranking mechanism; and the quantitative research design with data collection and analysis methods including pre- and post-conceptual exams, lecture question, open-ended surveys. This research was based on a quasi-experimental mixed-method design a focus on student performance on higher order conceptual questions, and open-ended survey at the end of semester about their perception toward writing to learn ad implementing SWH. Results from the qualitative and quantitative component indicated that implementing SWH approach has notably enhanced both male and female conceptual understanding and perception toward chemistry and implementing SWH. It is known that there is gender gap in science, where female have lower perception and self confident toward science. Interestingly, my findings have showed that implementing SWH helped closing the gap between male and female who started the semester with a statistically significant lower level of conceptual understanding of chemistry concepts among females than males.