Name:
Total:
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Lab: Reaction Rates and Stoichiometry
Purpose: To measure the rate of a reaction using an easily observable variable, to calculate an
instantaneous rate of reaction from data collected, and to use stoichiometry to predict the rate
and amount of other reactant(s)/product(s) consumed/produced.
Background: A series of steps create the overall equation below for the dissolving of sodium
bicarbonate.
NaHCO3(s) ==> CO2(g) + NaOH(aq)
Method:
1) Place 100ml of water in a small beaker. Record this mass.
2) Place a baking cup on the scale. Zero the scale. Place two Alka-Seltzer tablets onto the
baking cups. Record this mass.
3) Add the masses from steps 1 and 2. Record this mass in a data table. This will become
your initial mass.
4) Place the Alka-Seltzer tablets into the water while the beaker is placed on the scale.
Record the mass every 30 seconds for 5 minutes. Record these masses in a data table.
Data: (3 marks)
1) Mass of beaker with water ____________
2) Mass of Alka-Selttzer tablets___________
Time (s)
Mass of system
(g)
CO2 (g)
produced
0
30
60
90
120
150
180
210
240
270
300
Analysis: (22 marks)
1)
2)
3)
4)
5)
Calculate the total mass of NaOH produced (2)
Calculate the total mass of NaHCO3 consumed. (2)
What is the concentration of NaOH in the final solution? (2)
Graph the mass of CO2 produced. (7)
What is the instantaneous rate of production of CO2 at 120 seconds in g/second?
Show your work on the graph. (4)
6) What is the instantaneous rate of production of CO2 in mol/s? (The Co2 produced is
escaping into the environment, so it will not have a concentration.) (2)
7) What is the instantaneous rate of production of NaOH in M/s at 120 seconds? Show
your work. (3)