With the growing attention directed towards ChatGPT and its applications in education, this study explored its impact on various variables pertaining to student learning. Specifically, an integrated theoretical framework was used to investigate the factors that influence student problem-solving and critical thinking abilities when using ChatGPT for educational purposes. Data was collected from 687 students by questionnaire survey. The research model was evaluated using both first order and second-order factors through partial least squares structural equation modeling analysis. The results revealed significant relationships and mediating and moderating effects within the proposed conceptual framework. These findings underscore that learning motivation directly affects learner engagement and problem-solving skills. Moreover, learner engagement was found to positively influence problem-solving and critical thinking tendency. Problem-solving skills have also emerged as pivotal and significant factors influencing critical thinking tendencies. The study also confirms the moderating roles of students' mental attributes, which amplify the relationship between learning motivation, learner engagement, and problem-solving. The partial least squares multigroup analysis method was used to ensure the generalizability of our model. The concluding section discusses both the theoretical and practical implications for educational settings.