Stoichiometry is one of the major concepts in chemistry. Conceptual understanding in stoichiometry is crucial for any student taking chemistry as a subject as many areas in chemistry are highly related to this conceptual understanding. Many previous researches found out that students poses a very low conceptual understanding and they also poses many alternative conception related to stoichiometry. Dahsah. C; Coll. R. K (2007), found that students conceptual understanding seem to be related with their ability to solve numerical problem in stoichiometry. Problem solving strategies used by students could indicate the alternative conceptions possessed by them and also their ability to solve a problem. Students need a proper conceptual understanding in order to develop meaningful thinking ability, use and apply that understanding in meaningful ways, (Roth, 1990). However, students seem to be lacking when it comes to conceptual understanding and often resort to rote learning whereby they simply memories certain problem solving methods to answer exam questions. Researchers also found that some high achievers tend to solve numerical problems in stoichiometry based on memorization rather than reasoning, out of proper conceptual understanding (Tóth. Z and Sebestyén. A, 2009). The ability to solve problem successfully does not indicate deep conceptual understanding and these students will stumble when they are exposed to problems which are little bit different from the usual one as they cannot figure out the solution although it is still based on the same concept. Therefore it is essential to get the concept first before anything. Fach. M, Boer. T and Parchman . I (2006) stated that many researchers think that concepts are very difficult to understand. They also found a strong connection between sound conceptual understanding and the ability in problem solving related to stoichiometry.
Background of the study
There are many studies that had been carried out related to stoichiometry over the decade. However it is still under study as it is still found to be difficult among students and teacher. Stoichiometry is a very basic and fundamental concept in chemistry this could be another reason why strong emphasis is given to it (Fach. M, Boer. T and Parchman . I, 2006). Marais. F and Combrinck. S (2009), stated that Chemistry is considered to be one of the toughest subject and a subject with the lowest passing rate even among undergrads due to their inability to solve problems related to stabilizing equations which is much related to stoichiometry. They also found in their study that all conventional form of lecture presentation failed to make any significant impact on the success rate. This indicate the need for new way of teaching stoichiometry and also the importance in forming a deep n strong conceptual understanding related to stoichiometry to ensure that the students have a strong base in chemistry. Apart from that stoichiometry is also considered difficult by many educationist and students as it requires the students to switch from thinking about concrete aspects of matter to more abstract thinking concerning aspects of particles. They will have to enhance their conceptual understanding and these concepts are often too difficult to grasp and may be discouraging for the learners (Fach. M, Boer. T and Parchman . I, 2006). This may be a reason why the students resolve to easy way out that is by memorising steps to solve problems rather than understanding why certain calculation is done in certain ways. They just focus on the step by step by process and some educationist drill the students in order they get the method of solving the problem rather than teaching them the concept or making moves to help the students to reason out certain methods for better understanding. Some educationists believe that...