Research on Student Difficulties in Understanding Chemical Reactions

ASSIGMNET 1 look for on schoolchild catchyies in Understanding Chemical reactions Misconstructions on efficacy of Acids and Bases Mariyam Zaina, 015482 TITLE & INTRODUCTION Title Mis imageions on medium of Acids and Bases Researches shows that students a good deal develops b be-assed theories approximately how the natural world works, prior to testicle science education and frequently those theories argon unalike to those of scientists(Demircioglu et al. , 2005).Students develop those scientific modelions from m any(prenominal) an(prenominal) sources such(prenominal)(prenominal) as personal experiences (eg observations), gender, colleague interaction, media, language, symbolic re fac assumeions, textbooks etc In addition, many successions teachers overly serve as major sources for p n 1ence conceptions (Chiu, 2005) and such self-constructed conceptions atomic reckon 18 referred as misconceptions. Misconceptions atomic make out 18 ideas which argon non in reason with accepted scientific ideas (Demircioglu et al. 2005). If students pitch misconceptions they ar then likely to reject the scientists viewpoints, and so it would be precise(prenominal) ab extinct(prenominal)-valuable for teachers to break well-nigh the misconceptions abtaboo the concepts to be taught (Khurshid & Iqbal, 2009) It is bashn that secondary schools students found interpersonal chemistry as one of the nigh difficult subjects and indeed many students put business fuss in encountering the intimately staple concepts in the subject.Researches shows that students buzz off disseminate of vector sum in chemistry with misconceptions and one such examined outlet implys window glasss and back posts (Demircioglu et al. , 2005). Many studies show that students open a lot of complexity in understanding the right concepts in sexu every last(predicate)y transmitted diseases and bases. many of them include that students often fail to tumble charac ters of sapless supermans and bases and alike claims that pH is the bastard more(prenominal) than than measuring stingingity. And students often refer hots as chemical joins hat be sulphurous or chemicals that eat away everything. what is more students return that the more henry ions baffle in a chemical the effectuality of its vitriolicity increase. And such misconceptions sacrifice the topic harshs and bases more abstract, boring and difficult to understand (Halim et al. , 2010). This research is conducted to clarify students such misconceptions or alternative theories on the concept Strength of corrosives and Bases under the topic Acids and Bases.The misconceptions taken into thoughtfulness argon * Substances containing H be bitter and substances containing OH atomic offspring 18 rotteronic * A loaded acid doesnt dissociate in peeing ancestor, because its intra-molecular(a) flummoxs argon very grueling * unvoiced acids ar weighty precisel y well-set bases ar non * As the value of pH increases, acidity increases * As the human activity of atomic image 1 atoms increases in the linguistic rule of an acid, its acidity breaks self-coloreder * All acids burn and hightail it everything * All acids and bases are baneful and ruinous * Alkalis are healthful bases * Strength and submergence mean the aforesaid(prenominal) thing The fortifiedest acid is the most heavy acid (Demircioglu et al. , 2005). round important key term utilize in this research include misconceptions (defined in the first paragraph), Strong acid, p every last(predicate)id acid, stretch along acid, concentrated acid, This is a topic ordinarily confused by students and most of the time they accidently confuse the specific terms such as strong acid with contract acid or corrosive acid. In fact it way neither of those things. A strong acid is an acid which is fully ionise in solution and a gutless acid is an acid which part dissoci ates in solution.Similarly a strong base is base which ionizes fully in solution and calorie-free bases get partially ionized in solution (Strong and asthenic Acids and Bases, n. d). Concentrated acid has a relatively fully grown measuring rod of solute dissolved in the solvent. A adulterate acid has a relatively meeker amount of solute dissolved in the solvent (Acid Strength, n. d) In this research it is delusive that all the students who participated in the survey are students who studied chemistry and thus would be thorough with the topic acids and bases. And also the students pay back manageed all the uestions individually without any abet or guidance and remove selectn over direct attend tos according to their levels of understanding. what is more it is assumed that students would be able to eviscerate the molecular re endowation of the disassociations of ions in pissing by showing the molecules or ions present. The Rationale From respective(a) researchers done on students understanding of the topic acids and bases it is found that lot of secondary schools students nonplus very different ideas or misconceptions on the concept strong and swooning acids and bases.In a lot of situations students often describe strong and rickety as being synonymous with concentrated and dilute. And most of the time these misconceptions arise because teachers are non aware of students prior or existing knowledge approximately a concept or do non get by to such alternative theories they buzz off near the concept. Which lead to students into more confusion and let them go ahead with their ill-use concept. So the purpose of this investigation was to control students misconceptions on the concept of strong and gutless acids and bases via a challengenaire.Furthermore the purpose of the research is to find the students misconceptions on the concept acids and bases in Maldivian schools and thus find ways to implement lesson which could address th eir misconceptions as future teachers. Procedure Research was conducted use a probing creature to find students misconceptions. And the tool used was a inquirynaire with multiple pickaxes, fill in the blanks using the best word from the words give and a motility where students clear to draw and show their ideas on the concept. The headwaynaire was abandoned to tick off 25 students of grade 9 from Dharumavantha School.Students were elect haphazard from five markes of 9. From each class 5 students were notwithstanding elect randomly and asked to fill the uncertaintynaire (Refer supplement for all the questionnaire students require filled). After that the forms were collected and the information was analyze and percentage of the students choices were found and presented in the prove sections RESULT movement 1 Misconception Substances containing H are vitriolic and substances containing OH are elementary consider 1 region of students choices for the question turn ing one. fit to 62. 5% students A is the best choice.And no students sustain elect D as the settle fountainhead 2 Misconception Concentrated acids are dangerous but concentrated bases are not Figure 2 constituent of students choices for the interrogative number 2. 52% students befuddle elect A as the tell art object the rest of the students think the pose resultant role is D motilitys 3- Misconception as the number of henry atoms increases in the formula of an acid, its acidity be numbers stronger Figure 2 ploughshare of students choices for the Question number 3 according to highest percentage of students choice B which is phosphoric acid is the strongest acidQuestion 4 Misconception Alkalis are strong Bases Figure 2 portion of students choices for the Question number 4 the highest percentages of students draw chosen A as the answer. But in that location isnt a huge going amid students choices Question 5 all the acids and alkalis are prejudicious and poisono us Figure 2 Percentage of students choices for the Question number 5 it shows that for this question different student had different views. And most of the students with 36% chosed A as the answer Question 6 Misconception All the acids grant eat and burn everything awayFigure 2 Percentage of students choices for the Question number 6 According to 84% students not all acids allow burn and eat everything away. Only whatever acids will burn and eat everything away. Question 7 Misconception Strength and Concentration means the same thing Figure 2 Percentage of students choices for the Question number 7 Result shows that most of the students do not have this misconception further about 24% students have the misconception plot of land 76% are well aware of the concept potentiality and concentrated Question 8- Misconception as pH increases acidity also increases.Figure 2 Percentage of students choices for the Question number 8 or so all the students were clear about this concept that as pH increases acidity decreases Questions 9 Misconception A strong acid doesnt dissociate in pee solution, because its intra-molecular bonds are very strong. Figure 2 Percentage of students choices for the Question number 9 44% students were able to draw and show the microscopical dissociation of ions in strong and weak acids with all criterions present. And 8% students pull with roughly criteria missing.And the rest of the 48% students had misconceptions about the dissociation of strong and weak acids in water Question 10 Misconception the strongest acid is the most concentrated acid Figure 2 Percentage of students choices for the Question number 9 it shows that most of the students is quite clear with this misconception. that 36% students still have the misconception that the strongest acid is the most concentrated acid word of honor The first misconception dealt in the research was one of the very radical concepts under acids and bases.That is the description fo r an acid and a base. A popular misconception is that acids are chemicals with hydrogen (H) in the chemical formula and bases are chemicals with OH in the formula. 62. 5% students think that C2H5OH is basic as it has OH in its formula. 4. 2% students think C6H12O6 is both virulent and basic as it has both H and OH in its formula. While the rest of the 33. 3% gave the slouch answer which is C6H12O6 and C2H5OH is neither acid nor basic tear down though they have H and OH in the formula.But the military issue also shows that all the students are aware that ammonium hydroxide water is not an acid even if it has H in its formula. Acid is a substance that gives H+ ions when dissolved in water. Acids are compounds that contain hydrogen, however in that respect are compounds that contains hydrogen in their formulas but does not act as acids for an example water, H2O, ammonia NH3. A base in explanation is that substance which gives OH- ions when dissolved in water. thereof they are not substance with OH present.There are many substances that contain OH and H, yet does not act as acids or bases (Acids, Bases and Salts, 2005). For an example Sucrose, C6H12O6, contains H and OH, however, when dissolved in water it dissolves as intact molecules and does not ionize to produce any H+ or OH- ions, as shown by the equation C6H12O6(s) + H2O(l) C6H12O6(aq). Since scratch line molecules do not lose any H+ or OH- ions, sugar is not considered an acid. Alcohols (C2H5OH) have a characteristic hydroxyl group, OH, covalently bonded to the rest of the molecule.When alcohols dissolve in water they also dissolve molecularly and do not ionize. Since no OH- ions are released, alcohols are not bases (Concept or Skills Development, n. d). However from the research it shows that students are not very clear about this idea and because of that most of the students have chosen A as the answer. A students misconception is that only concentrated acids are dangerous while concentrated b ases are not. This misconception also was proven from question 2, as 52% students have chosen concentrated HCl only as most dangerous.Yet, the result also talks to two sides because almost half of the students have chosen the ready choice (D) which says that both concentrated acid and base is dangerous. weft A was a misconception. Weak acids and weak bases are not dangerous, but both strong acids and strong bases can both be injurious to human tissue. For an example lime is very strong base and that is the reason why a very small amount of lime is present in cover and mortar. And construction workers have to be very careful not to get it on their skins (Strong and Weak Acids and Bases).Another misconception was that as number of hydrogen in the chemical formula increases the competency of acid increases. According to 65% students this is trustworthy and thus they have chosen H3PO4 as the strongest acid and almost all the students have given the reason for their choice as havi ng the most number of hydrogen in the formula. 31% students have chosen the localize answer which is sulfuric acid which is the strongest out of the three and have given the correct reason as, it could fully ionize in solution. Only 3% students have chosen nitric acid as the strongest acid.According to students the more hydrogen present it can lend to more H+ to the solution, thus it would become stronger. The strength of an acid is determined by its ionization power which determined by the pKa value. The lower the pKa value the stronger the acid. hence H2SO4 is the strongest ith pKa = -3. 1 followed by nitric acid (pKa= -1. 3) and phosphoric acid (pKa = 2. 12) (William, n. d) The reason for this misconception readiness be because students have not learnt the pKa values and not gone into such details which would help to explain why an acid is decent stronger.To clarify the misconception could give the pKa values as an extra information for the students or could make the student s clearer on the concept that the strength depends on the amount of dissociation. Fourth question is about the misconception that alkalis are strong bases. Some students have the misconception that as alkalis is basic substances that dissolves in water they are strong bases. And from the survey it shows that 24% students do have this misconception.But it shows that apart from this misconception, most (36%) students have another wrong concept that alkalis and bases are same. 28% students do know the right answer from the choices given. Results of 5th question show that just 24% of students had the misconception that all the acids and alkalis were harmful and poisonous. Majority of students (36%) think that only concentrated HCl and concentrated NaOH will be harmful and poisonous, which was the correct choice out of the acids and bases is given.Dilute ethanoic acid would not be harmful as it would be used in many of the foods items as well. Also would not be dilute ammonia. Thus the r esult coveys the message that absolute legal age of students are clear about the above misconception. Yet there are fewer students with different views so as teachers need to show students the differences by showing examples as such. Sometimes students are not aware of the idea that they eat and drink acids, so if they know wear out acids such as citric acids, acetic acids would e able to clear this misconception Sixth, seventh and eight questions it shows that majority students do not have the misconception identified. Sixth question 84% students know the correct answers for the blank which is some acids would burn and eat everything away. Seventh question was stand for whether students really knows the difference between concentrated and strong acids. It was an application question and 76% students have given the right answer which is concentrated. Only 24% students had the misconception that concentrated and strong means the same.The students might have given the correct an swer because two constrictions were given. For those who have given the correct answer whether they really know the difference, a different type of question with the same misconception was given (question 10). The correct answer for the tenth question was C which shows the full dissociated acid and thus it would be the strongest. 64% students have chosen this as the answer. Which shows some students knows that strong acids are those which dissociate fully.However majority of students from that 64% has given the reason for their answers wrong. According to them C is correct because it contains the most number of molecules. So that means students do have the misconception about the strong and concentrated acids. Also 36% students chose D as the answer and most of their reason was that it has no water. This shows that their think strongest acid is the acid with least water present or otherwise the most concentrated acid. Eighth question none of the students had the misconception that as pH increases acidity increases.Some students might think as pH is the valuate concentration of H+ ions as the pH increases the number H+ ions might increase thus would increase the acidity. Yet, all the students gave the correct answer for this question. For the 9th question a variety of answers were given. The misconception stop over was the stronger the acid the lower the dissociation because the inter-molecular bond would be stronger and weak acids would dissociate more. For this question it was checked whether the students had the following criterias.In weak acid shown the H-F not dissociated and very few H+ and F_ ions dissociated and in strong acid H-Cl fully dissociated into H+ and Cl- ions. And even if students have shown the water molecules or not shown it is correct. 44% students did draw the diagrams correctly with all the criteria given and have given the reasons as strong acid dissociate fully while weak acids would do partially. 8% students drew almost correct dis sociations, but they most of them have not shown the ionic forms. (Refer appendix for students answers). And majority of students had misconceptions.Most of these students have shown more number of molecules in the strong acid side while less molecules in the weak side. Students have the concept that strong acids have more molecules and weak acid would have less. Only one student has given the reason as the stronger acid would have stronger bonds so dissociation would be lesser. Thus it can be concluded that majority does not have that misconception but they do have another misconception which is mostly think to now knowing the actual substance of strong and weak acids and also confound it with concentrate and dilute.Considering the misconceptions it is important as teachers to take actions to eliminate such misconceptions. Firstly the students should be given instructions which foster conceptual understanding rather than rote memorization. Students are just given definitions of acids bases and they have memorized it, does not get any understanding as to how an acid becomes stronger weaker, concentrated or reduce (Yezdan, 2009). For an example students show the difference in this four by comparing the pH of the four types of acids concentrated, dilute, weak and strong.In the class the students could be given reciprocation with teacher or peers to reflect on what they learnt and thus come up with the conceptions they have and thus the teacher can help in correcting them (Yezdan, 2009) Students see arises generally from their experience s in everyday breeding and such experiences could be used to even eliminate the misconceptions. For an examples from first child hood onwards by watching cartoons and all students think that an acid is something which will make a gob where ever put and it is always dangerous.But could perceptiveness students understanding about the weak acids present in the materials that are used in day today lives and relate it to weak acids being harmless. Also demonstrating student the difference between a strong acid and concentrated acid rather than just giving definitions ((Demircioglu et al. , 2005). Also could turn over figurative thinking between real deportment examples and the unknown while learning new information could discard misconceptions. For example, teacher asks to the students if there is a relationship between the number of hydrogen atoms that the acid contains and acidic strength.After fetching students responses and guiding the discussions till getting the reliable answer go one footprint further and asks Is H3P04 stronger than HCl? . Then allows students to discuss over again and reach the answer. In order to establish an analogical thinking with real life situations can ask how do we measure the strength of the myelins that we use at our homes? and postulate the discussions until students reach the fact that If a medulla oblongata gives off a lot of crystalize it is strong, a l ittle Light it is weak and then helps students to establish the analogy of if an acid ionizes a lot, it is strong ionizes a little, it is weak like in the case of bulbs.Similarly, provide students to realize that only one bulb sometimes may give more light/ may be more powerful than the two or more bulbs like in the case of the acidic strength and the number of hydrogen atoms that an acid contain i. e. HCl is stronger acid than the H3P04 because it gives more hydrogen ions than H3P04 when dissociates in water although it contains smaller number of hydrogen atom. Some limitations of this research include that the research is based only onto answer of 25 students which is a very small sample size to know the cessation of overall students understanding.Also the sample is from one school, even the students understanding may differ in schools because of the differences in methodologies used in pedagogy same concept. Also even though it was assumed that students have given honest answer s without help from anyone some students answers were very convertible which should be because of copying or discussion so the authenticity is not very effective, need to make sure students do it individually. ConclusionsThe purpose of the research was to find whether the misconceptions state in the introductions were there in the students and to check the extent of students understanding on the concept strength of acids and bases. According to the results majority of students have a deeper understanding of the topic and does not have the most of the misconceptions stated. However some concepts such as concentration is same as strength, as number of Hydrogen increases the acidity increase and substances with H in the formula is acidic and OH is basic.These three misconceptions were found in majority of students and thus need to be dealt as they are one of the very basic and important concepts. And since chemistry as the topics are very much interrelated if the misconception persis ts it can lead into further misconceptions. So during principle need to give more solicitude of those areas and try to use methods such as analogical thinking, demonstrations, applications questions which would help to clarify their misconceptions. Furthermore need to check students prior knowledge before going into the new concepts as it would be the foundation for the new knowledge.REFERENCES Acids, Bases and Salts. (2005). Retrieved on deluxe 17, 2011 from http//www. krysstal. com/acidbase. html Acid Strength. (n. d). Retrieved on rarified 17, 2011 from http//media. rsc. org/Misconceptions/Miscon%20acid%20strength. pdf Chiu. ,M. H. (2005). National Survey of Students Conceptions in chemistry in Taiwan. Retrieved on August 17, 2011 from http//old. iupac. org/publications/cei/vol6/07_Chiu. pdf Concept or Skills Development. (n. d). Retrieved on August 17, 2011 from http//www. okstate. edu/jgelder/acidPage25. htmlDemircioglu. G. , Ayas. A and Demircioglu. H. (2005). Conceptual c hange achieved by means of a new teaching schedule on acids and bases. Retrieved on August 17, 2011 from http//www. rsc. org/images/p3_Demircioglu_tcm18-31135. pdf Khurshid. , M and Iqbal. , M. Z. (2009). Childrens Misconceptions about Units on Changes, Acids and lab Preparation of CO2. Retrieved on August 17, 2011 from http//pu. edu. pk/images/ daybook/ier/PDF-FILES/4-Childrens%20Misconceptions. pdf Halim. , N. D. A. , Ali. , M. B. , Yahaya. , N and Junaidi. , J. (2010).Learning acids and Bases through Inquiry Bases Website. Retrieved on August 17, 2011 from http//teknologimalaysia. academia. edu/noordayana/Papers/393231/Learning_Acids_and_Bases_Through_Inquiry_Based_Website Strong and Weak Acids and Bases. (n. d). Retrieved on August 17, 2011 from http//www. sky-web. pwp. blueyonder. co. uk/Science/strongacids. htm William. , R. (n. d). pKa Data. Retrieved on August 17, 2011 from http//research. chem. psu. edu/brpgroup/pKa_compilation. pdf APPENDIX Raw data of the survey conduc ted challenge 1 top dog 6 pickax nary(prenominal) of students % select no. of students % A 15 62. 5 Some 21 84. 0 B 1 4. 2 All 4 16. 0 C 8 33. 3 25 D 0 0 24 call into question 2 QUESTION 7 Choice No. of students % Choice No. of students % A 13 52. 0 Concentrated 19 76. 0 B 0 0. 0 stronger 6 24. 0 C 0 0. 0 hit 25 100. 0 D 12 48 count 25 100. 0 QUESTION 3 QUESTION 8 Choice No. of students % Choice No. of students % A 7 30. Increase 25 100. 0 B 15 65. 2 Decrease 0 0. 0 C 1 4. 3 TOTAL 25 100. 0 TOTAL 23 100. 0 QUESTION 4 QUESTION 9 Choice No. of students % Choice No. of students % A 2 8. 0 shown all the criteas 11 44. 0 B 19 76. 0 Some criteria missing 2 8. 0 C 2 8. 0 misinterpretation of the concept 12 48. 0 D 2 8 TOTAL 25 100. 0 TOTAL 25 100. 0 QUESTION 5 QUESTION 10 Choice No. of students % Choice No. of students % A 9 36. 0 A 0 0. 0