CHEMISTRY PLANNING AND DESIGNING SBA FORMAT (2021) Wolmer’s Boys’ School Experiment # Date Problem Statement / Observation (ALWAYS WRITE THE PROBLEM STATEMENT AS GIVEN BY YOUR TEACHER) Peter and Marc are two friends who enjoy banana chips as snacks during lunch time at school. Peter prefers St Mary’s banana chips because he thinks it is less salty and healthier than Chippie’s. Marc disagrees. Plan and design an experiment to decide which brand is the healthier option. Theory (optional) Textbook info…info from internet etc. Hypothesis This must be based on observations or prior knowledge and clearly stated in a form that is testable/measurable. St Mary’s banana chips will contain less mass of salt than Chippie’s and hence will be the healthier option. Aim This must be linked to the hypothesis. To determine and compare the mass of salt in St. Mary and Chippies banana chips using solubility. Apparatus and Materials List all materials and apparatus to be used in the method. Use apparatus generally found in a school laboratory. (It is helpful to write the method first then take the list of apparatus and materials from it). Beaker, measuring cylinder, timer, analytical balance, evaporating dish, Bunsen burner, tripod stand, wire gauze, distilled water, St. Mary banana chips, Chippie’s banana chips. Diagram of apparatus set up (OPTIONAL) Draw a set-up of the procedure. PLACE DIAGRAM HERE Method - Steps to be followed in the appropriate sequence and in PRESENT TENSE - how apparatus and materials will be used -Treatment of variables (all variables should be involved somewhere in the method) -Type of data to be collected and how the data will be treated 1. Obtain two large beakers. CHEMISTRY PLANNING AND DESIGNING SBA FORMAT (2021) Wolmer’s Boys’ School 2. Using a measuring cylinder, pour 250 mL of distilled water into each beaker. 3. Label one beaker as St. Mary and the other as Chippies. 4. Measure 50g of St. Mary’s banana chips and place in the beaker labelled St Mary. 5. Allow the banana chips to soak for 5 min. 6. Decant the water from the mixture into a pre-weighed evaporating dish. 7. Set up a Bunsen burner and place the evaporating dish on the top. 8. Allow the water to evaporate. 9. Determine the mass of the salt. 10. Record the results in a table. 11. Repeat steps 4-10 for Chippie’s banana chips. Variables Manipulated/ Independent variable is the parameter that is altered by the person carrying out the method. The brand of the banana chips. Responding/ Dependent variable is the parameter that changes in response to the manipulated variable. Mass of salt Control is the parameter which remains constant (same throughout) for the duration of the method. Volume of water, time Mass of chip Data to be Collected Show how data will be recorded, usually a table with the appropriate headings and units if applicable. No predicted results data is necessary in the table. Brand of Banana Chips St. Mary Chippie’s Mass of salt (g) CHEMISTRY PLANNING AND DESIGNING SBA FORMAT (2021) Wolmer’s Boys’ School Expected Results Predict the results that are expected based on the observations that would be made if the method is carried out. This is based on the hypothesis being tested. The value obtained for the mass of salt in St. Mary’s banana chips will be less than the value for Chippie’s. Interpretation of Expected Results / Treatment of Results (Applies to methods that require calculations) Give a statement of how the expected results will support or disprove the hypothesis. If it is a method that requires calculations, also list the calculations that are to be carried out using the results obtained. If the value obtained for the mass of salt in St. Mary’s banana chips is less than the value for Chippie’s then the hypothesis is proven to be true. If not, then the hypothesis is false. Treatment of Results Mass of salt = Mass of evaporating dish with salt-mass of empty evaporating dish Limitations/Sources of Error/Assumptions/Precautions These comprise factors that could affect the results. PRECAUTIONS MUST BE WRITTEN IN PRESENT TENSE. Limitations 1. Other substances could be present in the banana chips that combine with the salt during evaporation to give incorrect mass of salt. 2. Source of Errors 1. Incorrrectly measuring the mass of banana chips. 2. Volume of water may be incorrect if it is not read at the bottom of the meniscus. Precautions 1. Take a second reading/ repeat the readings from the measuring cylinder when reading the volume. 2. Ensure that the balance is properly calibrated. Assumptions 1. Assume that all of the salt present in the banana chips will dissolve in the time used for the soaking of the banana chips. 2. CHEMISTRY PLANNING AND DESIGNING SBA FORMAT (2021) Wolmer’s Boys’ School
