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Constructed Response . Topic 8: Acids, bases and salt
Set I: Properties of acids and bases and indicators
Base your answers to questions 29 through 30 on the information below.
A laboratory worker filled a bottle with a hydrochloric acid solution. Another bottle was filled
with methanol, while a third bottle was filled with a sodium hydroxide solution. However, the
worker neglected to label each bottle. After a few days, the worker could not remember which
liqui d was in each bottle.
The worker needed to identify the liquid in each bottle. The bottles were labeled A, B, and C.
Using materials found in the lab (indicator, conductivity apparatus, and pieces of Mg metal), the
worker tested samples of liquid from each bottle. The test results are shown in the table below.
Table of Tests and Results
Teacher Preview Copy
Test Results
Test Bottle A Bottle B Bottle C
Methyl orange indicator Yellow Yellow Yellow
Bromthymol blue indicator Blue Green Yellow
Electrical conductivity Conductor Nonconductor Conductor
Reactivity with Mg metal No reaction No reaction Reaction
Teacher Preview Copy
29. Using the test results, state how the worker differentiated 29.
the bottle that contained methanol from the other two bottles.
30. The worker concluded that bottle C contained hydrochloric acid. 31.
Identify one test and state the corresponding test result that
supports this conclusion.
31. If bottle C contains hydrochloric acid as concluded by the worker, 31.
name one chemical substance that is produced in the reaction
of the hydrochloric acid with the Mg metal?
32. Explain, in terms of pH, why the methyl orange indicator test 32.
results were the same for each of the three liquids.
33. Identify another metal on Reference Table J that will also react 33.
with the liquid is Bottle C .
Copyright©2010 E3 Scholastic Publishing. All Rights Reserved. SurvivingChem.com 395
Set I: Properties of acids and bases and indicators
Base your answers to questions 29 through 30 on the information below.
A laboratory worker filled a bottle with a hydrochloric acid solution. Another bottle was filled
with methanol, while a third bottle was filled with a sodium hydroxide solution. However, the
worker neglected to label each bottle. After a few days, the worker could not remember which
liqui d was in each bottle.
The worker needed to identify the liquid in each bottle. The bottles were labeled A, B, and C.
Using materials found in the lab (indicator, conductivity apparatus, and pieces of Mg metal), the
worker tested samples of liquid from each bottle. The test results are shown in the table below.
Table of Tests and Results
Teacher Preview Copy
Test Results
Test Bottle A Bottle B Bottle C
Methyl orange indicator Yellow Yellow Yellow
Bromthymol blue indicator Blue Green Yellow
Electrical conductivity Conductor Nonconductor Conductor
Reactivity with Mg metal No reaction No reaction Reaction
Teacher Preview Copy
29. Using the test results, state how the worker differentiated 29.
the bottle that contained methanol from the other two bottles.
30. The worker concluded that bottle C contained hydrochloric acid. 31.
Identify one test and state the corresponding test result that
supports this conclusion.
31. If bottle C contains hydrochloric acid as concluded by the worker, 31.
name one chemical substance that is produced in the reaction
of the hydrochloric acid with the Mg metal?
32. Explain, in terms of pH, why the methyl orange indicator test 32.
results were the same for each of the three liquids.
33. Identify another metal on Reference Table J that will also react 33.
with the liquid is Bottle C .
Copyright©2010 E3 Scholastic Publishing. All Rights Reserved. SurvivingChem.com 395
