Investigation of Mass of chemical reaction name: Won Chang date: November 17th Aim: How does changing Mass of citric acid affect Mass of CO2? Variables: Independent
Mass of citric acid
Mass of CO2
Temperature, water added until all reactions are dissolved
Control b) related
Mass of reactants 2 must be excess
Hypothesis: If the mass of citric acid is increased, the mass of CO2 will increase by linear relationship. According to the law of conservation of mass states that mass stays same before reaction and after reaction. It is neither created nor destroyed in a chemical reaction; meaning that the ratio of total mass in a chemical reaction will stay constant over time in isolated situation.Therefore, when the ratio of mass of citric acid (limiting reactant) and the mass of sodium bicarbonate (excess reactant) increases by 1:2.
Materials & Diagram of Set-up of Equipment (optional): 1. 2. 3. 4. 5. 6.
2 beakers (250 ml) 1 beaker (100ml) digital scale 2 stir sticks spatula wash bottle
Chemicals: 1. Water 2. Citric acid 3. Sodium bicarbonate(Baking soda) Diagram(optional):
Procedure/Method: 1. 2. 3. 4. 5. 6.
Measure the water 100 ml in the beaker Measure the citric acid(0.5g) on the digital scale. Measure the sodium bicarbonate (1g) on the digital scale. Pour the citric acid and the water into the beaker Measure the beaker with the digital scale for mass before the reaction Stir the solution until the citric acid is fully dissolved in water. (Stir it until it is transparent) 7. Measure the beaker with the digital scale for mass after the reaction 8. Put the sodium bicarbonate powder into the beaker 9. Observe the reaction and measure the mass of CO2 You need to explain how to get the mass of CO2 10. Repeat the process in step number 1~9 but increase the amount of citric acid by 0.5g and the mass of sodium bicarbonate by 1g.
Observations: a) Raw Data (collected during experiment - in your task books) i) Qualitative -bubbles formed after pouring the baking soda -after pouring the measured sodium bicarbonate, the reaction happened very fast -it was transparent when the citric acid was dissolved in water.
ii) Quantitative (Make a table.)
Baking Soda (excess)(g)
Citric acid (limiting)(g)
Amount of water (ml)
MMass ass of gas(g) (before and after)
1 - 0.8This should be two seaparate columns
2 - 1.6
3 - 2.2
4 - 2.8
5 - 3.6
6 - 4.2
7 - 4.8
8 - 4.9
b)Processed Data: (calculations made with raw data) Show any processed data tables. Staple your graph:
Baking Soda (excess)(g)
Citric acid (limiting)
Amount of water (ml)
Mass of gas(g)
Conclusion: By seeing the graph of citric acid and sodium bicarbonate, the hypothesis has been proven. The relationship between citric acid and CO2 is linear . The gradient of best fit line is 0.75. The graph clearly shows as the ratio of mass of citric acid(reactant) increases, the mass of product gas increases; furthermore, the rate of the reaction is constantThis graph tells us nothing about the rate of reaction.. When the mass of citric acid increased by 0.5 gram, CO2 is also increased by about 0.4 gram.
Evaluation: The points that are in a gradient of 0.75 is close to the line of best fit. If the points are on the line, it means that experiment was successfully done. The points are nearly close to the line of bestfit line and the graph supports my hypothesis because the CO2 increased when the mass of citric acid increased. The Data point L,F and G are far from the line because there might be some errors done during the experiment or the mass of the chemicals used for the reaction is not accurately measured. Meanwhile, the other points are very close to the line because the experiment is successfully done without any error in it and results a good data The result couldn’t be accurate because I only tried once. To make it more accurate, I have to try twice or triple time.and take an average of the values. Gas is really hard to be measured. Limitation of digital scale is that it can’t measure the gas accurately because it only has one decimal place and if we have a measurement of mass that shows the mass to three decimal place or a machine that can measure the weight of gas , it would be more accurate. When I moved the citric acid into the beaker by using a piece of paper, some citric acid dropped from the side of beaker or the paperThis should be part of you qualitative observations.. Since Citric acid is a limiting reactant, it will affect the result of the reaction. To deal with this problem, it’s better to use a funnel or small box when putting the Citric acid into the beaker.
Work Cited "Conservation of Mass." Wikipedia. Wikimedia Foundation, 15 Nov. 2012. Web. 18 Nov. 2012. <http://en.wikipedia.org/wiki/Conservation_of_mass>.
Science 10 - Criterion D - Investigation
Objective & Task Specific Clarification
1 to 2
3 to 4
5 to 6
focused & clear
Aim D1 State a problem or research questions that is _________. Hypothesis D2 Makes a hypothesis that is _______ and _______ explains it using scientific reasoning. Variables, Materials & Method
D3 Selects appropriate materials, writes a clear & logical method, mentions all of the relevant variables and how to control & manipulate them, and describe(s) how data will be collected and processed. a. Names ____ the independent, dependent, and control variables. (Variables)
c. _______ how to manipulate the independent variable and keep the control variables constant. (Method)
d. ______ how the data will be collected (using your materials and experimental set-up) (method)
b. Includes a(n) _______ list of materials & equipment. (Materials)
e. Writes (a/an) _____ method.
clear, logical & complete
Conclusion D5 _______ comment(s) on the validity of the hypothesis based on the investigation results. â—?
Compares results to theoretical expectations based on explained scientific works.
Attempts to or doesnâ€™t
D4 ______ evaluate(s) the method in terms of reliability and validity.
Attempts to or doesn’t
Comments on one or more of the following: ●
the measuring instruments: ○ the appropriate selection of, ○ the precision and accuracy of, ○ the uncertainties associated with, the size of the sample of data the sampling techniques/the number of readings or trials for each set of data, if the conditions of the experiment lead to valid data collection (were the control variables constant?), if the manipulation of the variables was appropriate.,
D6 ______ improvements to the method or further inquiry when relevant. Assessment Level Overall D Level
*Remember, for MYP Science, it’s generally the lowest score that is taken to determine your Criterion Level.
Self - Assessment: I predict my score will be 5. My predicted score is more than my actual score.
Science 10 - Criterion E - Investigation Self Assessment: Underline the descriptor you think you achieved for each section.
Criterion E Objective & Task Specific Clarification
1 to 2
3 to 4
5 to 6
E1 Collects ____ data.
a. Include a minimum of 8 data points. b. Record a reasonable range of data at evenly spaced data points. E2 _____ record data it in a suitable format. a. Include headings and relevant units for all data. b. Record qualitative data with appropriate descriptions . c. Record only relevant and all relevant data which sometimes includes controlled variable(s). d. For any tables, the IV should be in left column, and the DV in the right column. e. Where appropriate, indicate the source of uncertainty in a measurement. f. The number of significant digits should be appropriate to the measuring instrument used. g. Make the degree of precision (final decimal place) the same for each set of raw data. Processed Data
E3 Organizes, transforms and presents data using numerical forms ____.
with few errors
logically & correctly
Inconsistent with, lacks
Consistent with, lacks
A correct interpret ation of, includes
a. Include a title that describes both the IV and DV. b. Include a best-fit line if appropriate and its equation if it’s appropriate. c. Spread out the range of data points within the graph/chart. d. Include appropriate labels and units for axes on a graph and for parts of a chart. e. Display key calculations in a clear and sequential manner. Show one calculation example if the calculation is repeated. f. Make the degree of precision for processed data consistent with the raw data. Conclusion
E4a _________ a trend, pattern or relationship in the data. ●
From the best-fit line/chart, describe the type of relationship (proportional/ linear/ exponential/no) between the IV and DV.
E5 Draws a conclusion that is _____ the data and ____ a scientific explanation a. Use data, such as the equation of the bestfit line, to support your conclusions. b. Explain conclusion using reasoning that draws from accepted scientific theories or principles Evaluation
E4b ________ the reliability of the data Comment on the most relevant of the following regarding the reliability of the data: ● ● ● ●
Describe how close the points are to the line of best fit. Comment on the how close repeated measurements were together. Comment on the number of measurements taken. Comment on any obvious sources of error during measurement.
6 Self - Assessment: I predict my score will be 5. My predicted score is less than my actual score. Your Criterion E Score : ___ *Remember, for MYP Science, it’s generally the lowest score that is taken to determine your Criterion Level.
Science 10 - Criterion F - Investigation Self Assessment: Underline the descriptor you think you achieved for each section. Criterion F Objective Descriptor: The student:
Safety F1 Requires _____ guidance to work safely. a. listens carefully and remembers all safety
issues. b. follows safety guidelines. Equipment Use
F2 Uses materials & equipment ___________.
with some assistance
requires some guidance to
needs reminders to stay
a. listens carefully and remembers how
equipment works. b. respects the equipment & makes efforts to
maintain or clean the equipment. c. puts the equipment back in its proper place.
Responsibility F3 _____ work(s) responsibly with regards to the living and non-living environment. a. uses all materials for their proper usage. b. respects peers during investigations.
Individual Work Ethic F4 ___ on task during independent work. a. uses class time wisely to complete all in-
class tasks. b. works independently when told to do so. c. never copies other studentsâ€™ answers on individual assignments.
Your final Criterion F Self Assessment Grade __6_
Self - Assessment: I predict my score will be 6. My predicted score is more than my actual score. Reflection: 1. The section I can improve the most is ___________.I can improve that section by:
2. The most difficult part of the investigation was ___________, because
3. Iâ€™m pleased/not pleased with my score, because