Sodium hydrogen hydrogen carbonate is a compound whose molecular formula is NaHCO3. It has a wide variety of uses and is primarily primarily used as a leavening agent in baking hence the name baking soda. !hen NaHCO3 is treated with acetic acid CH3COOH it produces sodium acetate CH3COONa water and carbon dio"ide CO#. In this e"ercise we will perform this reaction and study its stoichiometry. stoichiometry.
Objectives: $t the end of this e"periment you are e"pected to have been able to% &roduce carbon dio"ide from sodium hydrogen hydrogen carbonate and acetic acid Study the stoichiometry of the reaction
Materials Needed:
'aking soda (inegar $ wide brimmed glass or clear plastic )ar with about * + capacity $ plastic bottle with screw cap , about -m+ capacity /easuring cup /easuring spoon $ large bucket or tub !ater $ small clear plastic bag with about # inches width
vide o camera. Take Take your video while you are doing the activity. You You will submit this as NOTE: Set up your video your output for the activity. activity.
Procedure: *. If your your )ar does not have have volume volume marking markingss yet use the measurin measuring g cup to pour pour * m+ of water water at a time and use a marker to record the height of the water at each addition. #. 0ill your big big tub with water water.. Submerge your your )ar with markings markings and 1ill it with with water. water. 3. 0ill about about half half of the the plastic plastic bottle bottle with with vinegar vinegar.. 2. /easure /easure *2 teaspoo teaspoon n of baking baking soda and put it in the the small clear clear plastic plastic bag. Cut the plastic plastic bag bag if it is too long.
1
-. Laboratory Exercise No.
001
Course Code
NSCI101
Description
General Chemistry I
Title of Activity
LABORATORY EERC!"E
Stoichiometry Page 2 of 6
-. 4rop the small plastic bag with the baking soda on the bottle with vinegar and immediate close the bottle. /ake sure that the baking soda does not react with the vinegar before the lid is tightly closed. 5. Shake the bottle until all the baking soda is consumed. 6he reaction is complete when no signi1icant bubbling is observed. 7. 89ou may need someone to help you with this part:. +ift the )ar upside down with markings while maintaining the mouth submerged in water. /ake sure no air is present inside the )ar. &ut the plastic bottle under water and carefully place the mouth of the bottle inside the )ar. Open the bottle carefully to release the carbon dio"ide formed from the reaction into the )ar. 6he water level inside the )ar should be decreasing as the carbon dio"ide is transferred. ;.
Data: *. If you have a weighing scale you can directly determine the weight of the sample used in the e"periment. If none you can estimate the weight of the sample. 0rom the baking soda container get the net weight of baking soda and determine how many tablespoons of baking soda are in the container from the Nutrition 0acts 8Serving si=e in teaspoons and No. of servings:. >et the weight of baking soda in *2 teaspoon. Net weight of baking soda in one container 8g:% ???? No of teaspoons of baking soda in one container% ???? !eight of *2 tsp of baking soda%???? #. (olume of CO# produced 8m+:% ?????
Questions: *. #. 3. 2. -. 5. 7.
!rite a balanced chemical e@uation for the chemical reaction. In this e"periment which reactant is limitingA !hich reactant is in e"cessA !hat is the molar mass of NaHCO3A How many moles of NaHCO3 are there in *2 tsp of sampleA How many moles of CO# should be produced from the sampleA How many moles of CO# are actually formedA !e can predict for the volume by using the ideal gas e@uation &(Bn<6 where &Bpressure (Bvolume nBnumber of moles
2
Laboratory Exercise No.
001
Course Code
NSCI101
Description
General Chemistry I
Title of Activity
LABORATORY EERC!"E
Stoichiometry Page 3 of 6
Laboratory Quiz: 1.
2.
3.
4. 5.
6.
6rue or 0alse% It is important to ensure that the baking soda does not come in contact with vinegar until the bottle is tightly closed to ensure that all gaseous product is captured. 6rue or 0alse% $lternatively we can measure the volume of the gas inside the plastic bottle and use it to determine the number of moles of carbon dio"ide produced by using the ideal gas e@uation. 6rue or 0alse% It is important to make sure that the water inside and outside of the )ar is of the same level before taking note of the volume of carbon dio"ide. 6his ensures that the pressure inside and outside of the )ar is the same. 6rue or 0alse% In the performed e"periment the limiting reagent is NaHCO 3. 6rue or 0alse% $side from carbon dio"ide other products of the reaction are water and sodium acetate CH3COONa. 6rue or 0alse% 6he balanced chemical e@uation to represent the reaction is% NaHCO3 G CH3COOH CH3COONa G H#O G CO#
7.
6rue or 0alse% !e can use the volume of the vinegar used to calculate for the theoretical yield of the reaction. 0or items ; to *# refer to the following lab data. Show your complete solution for all the @uestions. /ass of NaHCO3 sample 8g:% *.# g (olume of carbon dio"ide produced 8m+:% #- m+
8. 9. 10. 11.
12.
!hat is the molecular mass of NaHCO 3A How many moles of NaHCO3 are in the sampleA 6heoretically how many moles should be produced from *.# grams of baking sodaA How many moles of carbon dio"ide is produced in the reactionA 8se the ideal gas e@uation &(Bn<6 for the calculation assuming &B * atmE 6B#F; D and
3
Laboratory Exercise No.
Course Code
NSCI101
Description
General Chemistry I
Title of Activity
001
Stoichiometry Page 4 of 6
LABORATORY EERC!"E /ass of beaker 8g:% #;.#7 g /ass of NaHCO3 sample 8g:% *.#- g /ass of beaker and residue 8g:% #F.5 g (olume of concentrated HCl 8*#moles+: 8m+:% 2.5 m+ 13. 14. 15. 16. 17. 18. 19. 20.
!rite the balanced chemical e@uation for the reaction. How many moles of NaHCO3 are in the sampleA How many moles of HCl are there in the sampleA How many moles of HCl are re@uired to react completely with NaHCO 3A !hich reagent is in e"cess and which reagent is limitingA !hat is the theoretical yield of NaCl in gramsA !hat is the actual yield of NaCl in gramsA !hat is the percent yield of NaCl in gramsA
INSTR!TIONS "OR T#E STDENTS:
Save your video ile in “.mp4” or “.avi” format only. The ilename of your video should be “!"ast #ame$% !&irst #ame$ ' "aboratory ()ercise *!++$” ,pload your video to any video sharing website such as YouTube and -imeo. aste the link of your uploaded ile on the space provided for it in the "/S.
Rubric $or !%ec&in'
!riteria ()*
+
,
-
.
&articipation 83J:
sed time well in lab and focused attention on the e"periment
sed time pretty well. Stayed focused on the e"periment most of the time
4id the lab but did not appear very interested. 0ocus was lost on several occasions.
&articipation was minimal or student was hostile about participating
Safety 8*J:
+ab is carried out with full attention to relevant safety procedures. 6he
+ab is generally carried out with attention to relevant safety
+ab is carried out with some attention to relevant safety
Safety procedures were ignored andor some aspect of 4
Laboratory Exercise No.
001
Course Code
NSCI101
Description
General Chemistry I
Title of Activity
Stoichiometry
LABORATORY EERC!"E
4ata collection 8*J:
Calculations 82J:
Conclusion 8*J:
Page 5 of 6
setup e"periment and teardown posed no safety threat to any individual.
procedures. 6he setup e"periment and teardown posed no safety threat to any individual but one safety procedure needs to be reviewed.
procedures. 6he setup e"periment and teardown posed no safety threat to any individual but several safety procedures need to be reviewed.
the e"periment posed a threat to the safety of the student or others.
/easurements are both accurate and precise. Observations are very thorough and may recogni=e possible errors in data collection. !ork is neat and organi=ed. Includes appropriate symbols units and signi1icant digits. $ll calculations are shown and the results are correct and labeled appropriately.
/easurements are accurate with reasonable precision. Observations are thorough. !ork is generally neat and organi=ed. Includes symbols units and signi1icant digits.
/easurements are somewhat inaccurate and very imprecise. Observations are incomplete or recorded in a confusing way. 6here are 3 or more minor errors using symbols units and signi1icant digits or # ma)or errors. Some calculations are shown and the results labeled appropriately.
/easurements are incomplete inaccurate and imprecise. Observations are incomplete or not included. Symbols units and signi1icant 1igures are not included.
Conclusion includes whether the 1indings supported the hypothesis
Conclusion includes whether the 1indings supported the hypothesis and
Conclusion includes what was learned from the e"periment.
No conclusion was included in the report O< shows little effort and re1lection.
Some calculations are shown and the results are correct and labeled appropriately.
No calculations are shown O< results are inaccurate or mislabeled.
5
Laboratory Exercise No.
001
Course Code
NSCI101
Description
General Chemistry I
Title of Activity
Stoichiometry
LABORATORY EERC!"E possible sources of error and what was learned from the e"periment.
