1. MOST COST-EFFICIENT BRAND OF BAKING SODA Keerthana Sundar, Deepa Selveraj, Desiree Chew and Amanda Lee from 211

2. Introduction  The purpose of this Research Studies project is to find out the most cost-efficient brand of baking soda.  This knowledge we acquire will be helpful to professional bakers and others who frequently use baking soda so that they can maximize the money spent on the baking soda.  We chose to embark on this project as we realised that many people nowadays use baking soda, without realising the science behind it, and how to maximise their money.

3. Research Questions  Which brand of baking soda is the most cost- effective?  How do you determine the most cost-effective baking soda?  What are the differences between baking powder and baking soda?  How does baking soda work?

4. Hypothesis  The greater the concentration of sodium bicarbonate in the baking soda, the more effective it is, for lesser amount of baking soda is needed to be used.

5. Brands that we used  Arm and Hammer  Bake King

6. Background Information – what is baking soda?  sodium bicarbonate (NaHCO 3 )  When mixed with acid liquid, releases carbon dioxide, which causes fizzing.  NaHCO 3 + H+-----> Na+ + H 2 0 + CO 2 (soda) (acid) (sodium) (water) (gas)  Recipes that use baking soda for leavening always have an acidic ingredient.

7. Difference between baking soda and powder Baking SodaBaking Powder IngredientsSodium Bicarbonatecombination of baking soda and a few other ingredients, and most importantly a dry acid Type-1) Double-acting - The first "action" occurs when baking powder is wet -The second "action" occurs when baking powder is heated 2) Single-acting Required for reaction to occur AcidWet ingredients (dry acid and baking soda will react)

8. Methodology  Back Titration: - We added 40 ml of 0.2 M Hydrochloric acid (HCl) to 0.2 g of baking soda to react the baking soda. - The excess acid which had not been reacted is then titrated using 0.x M sodium hydroxide (alkaline)  Titration: - Releasing alkaline from a burette to excess acid + screened methyl orange (indicator) in a beaker - when the indicator turns green, it shows that the excess acid has completely reacted

9. Process of titration (using Bake King baking soda) Bake King + hydrochloric acid, before being titrated. Pinkish colour is due to the addition of screened methyl orange. The colour shows that the content of the Erlenmeyer flask is acidic. After titration, the screened methyl orange indicator turns green. This signifies that the solution has reached the ending point of titration.

10. Titration Keerthana and Amanda titrating the Arm and Hammer brand baking soda. After the ending point, when we are going to record our results, it is important to read at the bottom of the meniscus in the burette.

11. Methodology  Advantages of using titration/back titration: - gives us the exact readings of up to 0.1 ml that are extremely accurate as a burette is used.

12. Methodology  The lesser the alkaline needed to react with excess HCl, the more cost effective the baking soda  This is because the amount of sodium hydroxide in the baking soda is higher in order to have reacted with a larger portion of the 40ml hydrochloric acid  Higher amount of acid  larger concentration of NaCO3  the more effective the baking soda Reacted HCl – amount of NaCO 3 in baking soda Excess unreacted HCl Alkaline needed to react with excess HCl

13. Results

14. Data Analysis

15. Conclusion

16. Reflections of the project  What we feel we have done well… Working well as a team Working with tight deadlines, such as coming up with the proposal, doing the experiment and getting results within a few sessions.  What we feel we need to improve on… Should have tackled the issue from different angles, we could have used more methods to validate our results.  Limitations of the project… That we don’t have apparatus to make our own cost- effective brand of baking soda.

17. Extension of project  Repeat this experiment more times, to get even more accurate data, with less errors.  We would like experiment and find out how we can ascertain the most cost-effective brand of baking powder. Titration may not be the best method to do so – we realised – because baking powder already contains acid.  Using the results we have gathered and apply it to baking real goods and see if our results hold true.  Share our results with those who can benefit from this and teach them how baking soda works.