Does Stoichiometry Suck Your Life?

Oh God if I knew what the easiest way to teach stoichiometry for my students, I would run that way! I do don't know other way to explain stoichiometry after trying all ways I'd known. For me personally stoichiometry is the best part of chemistry. The most I loved in chemistry when I was at school was stoichiometry. I'd take the highest score in this part but not in the characteristic of Periodic System because this part might ask you to memorize too much thighed statements as I didn't like to memorize. For me at that time when a kinda natural lesson asked you much to memorize, the lesson should go to a social science. No wonder then why I loved stoichiometry more than other parts of chemistry.

But, oh my, I still need to face the worst world of mine after years I've struggled it. With no good mood of the weakest heart I put my students' papers on the floor as I was sitting around and checked all points of each paper. I hoped I'd find something wrong with my check point on some papers, hoped I was blank when I checked one or more papers and I needed to recheck the score. But I couldn't find something to increase even one score of the papers.

It's the second exam of stoichiometry. I needed to rerun the same field because nobody had taken a good score in last stoichiometric exam. Every single person should take minimally 70 as her/his score to pass the exam. In the last exam, the highest score was 42 and the lowest one was 14. And now I'm rechecking results of the second exam. The highest score is 48 and the lowest is 8. There are some students take 8 and some others take 16.

If I'd be a uncared teacher or I'd leave this part after leaving the chemistry class, I'd love it but how I could because I'd accept students as my sons and daughters. Will a mommy leave her kids alone when they need her? So I'm here with my students' papers and just face their papers on as my paled face going much paler. I don't think my students too stupid to answer such stoichiometry questions. Yes they all were A-level questions but we'd discussed such questions in the class. When I asked them why they couldn't answer the questions and many didn't answer essay questions, they said they didn't understand the questions because they were in English and I used new vocabularies in many questions. Of course I won't give same questions with what we'd studied in the class. All vocabularies I used in those questions were just common vocabularies and as I used Cambridge tutorial to check the British English style on the questions.

I'm curious what's wrong with my students. Do I use wrong ways when I'm teaching stoichiometry? Should I change the way I teach them? Can someone out there tell me what better way i should run on?