One of the government's efforts to address 21st century
challenges and improve the quality of education in Indonesia is the
implementation of the independent curriculum. In 21st century
learning, students are required to have
4C skills to
be superior and capable of competing globally. One of the skills students must
possess to face the challenges of the 21st century is critical thinking. One
way to develop students' critical thinking skills in chemistry is by
implementing the project based learning model. The purpose of this research is
to produce student worksheet based a project based learning to develop critical
thinking skills among
vocational high school students expertise in industrial chemical engineering, specifically
on the colligative properties of solutions, as a suitable teaching material for
use in learning.The development research uses the 4D model, which is limited to
the development stage. The limited trial in this study was conducted at State Vocational High School 1 Cerme with
30 students expertise in industrial chemical engineering as the research
subjects during two meetings. The development of project based learning student worksheet was
declared suitable for improving students critical thinking skills in
colligative properties of solutions in terms of validity, practicality, and
effectiveness. In terms of validity, the developed student worksheet is
declared valid based of the content and construct validity criteria. In terms
of practicality, the developed student worksheet which obtained an average
percentage of 96.1% and supported by the results of relevant student activities
in the first and second meetings with 95,2% and 97,5%. In terms of
effectiveness, based on the n-gain score values of the majority of students,
who experienced an increase in critical thinking skills with an
n-gain score range of > 0.7 in the high category, supported by the results
of the paired sample t-test with a significance value of 0.000, with a
significance level ≤ 0.05, indicating a significant difference between the
pretest and posttest scores for critical thinking skills among students on the topic of colligative
properties of solutions. Based on the test results on the aspects of validity, practicality, and
effectiveness, it can be concluded that the students worksheet based on PjBL on
the colligative properties of solutions to train the critical
thinking skills of class X
students in industrial chemical engineering expertise is suitable for
application in learning.
Keywords: Students Worksheet, project based
learning, critical thinking skills, colligative properties of solutions,
osmotic pressure