SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
THIS IS A THREE PART LAB TO BE COMPLETED AND FORMALLY PRESENTED IN A
LABORATORY REPORT USING THE FORMAT SPECIFIED
Overall Expectations
A1. demonstrate scientific investigation skills (related to both inquiry and research) in the four areas
of skills (initiating and planning, performing and recording, analysing and interpreting, and communicating);
B2. investigate physical and chemical properties of elements and compounds
B3. demonstrate an understanding of periodic trends in the periodic table
EXPERIMENT 1
THE SEARCH FOR PATTERNS (THE REACTION OF METALS WITH WATER)
In this lab we will react a number of active metals with water. From our observations we will attempt to establish the
relationship between reactivity of an element and its position in the Periodic Table.
NOTE: Before proceeding with this lab, read over the entire procedure very carefully and have your instructor ask you and
your partner several oral questions. Have your data sheet initialed to indicate that this has been done. State the PROBLEM in
question form. You also need to have a prepared and signed list of hazards associated with any chemicals you are using for the
first time this semester..
CAUTION: FACE SHIELDS AND APRONS MUST BE WORN FOR THIS ACTIVITY! NEVER TOUCH
ANY GROUP IA ELEMENT WITH BARE HANDS OR ALLOW CONTACT WITH WATER, EXCEPT AS
DIRECTED.
HYPOTHESES: Predict whether or not you think Li, Na and K will have similar reactions and properties since they are in
family 1A. Also will reactivity increase or decrease from left to right? i.e. will Na or Mg be more reactive? Give reasons for
your prediction based on past learning, experience, hint you received from the research of safety of these elements…
PROCEDURE:
1. Half fill a clean 250 mL beaker with tap water and obtain a wire gauze with ceramic centre . Test the water with one
piece each of red litmus, blue litmus and pH paper. Record your findings. (This is called a control.)
2.
Using a square of paper towel (folded twice to four thicknesses ) obtain a piece of lithium form your instructor.
Observe how it is cut so that you can describe its appearance and hardness. Record this on your data chart.
3.
Gently dab the adhering oil from the metal using the corners of the paper towel. Stand at arm’s length away from the
beaker. With the metal on the paper towel in one hand and the wire gauze directly above it in the other, carefully
allow the metal to roll into the beaker of water. Immediately lower the gauze onto the beaker. When the reaction is
complete test the resulting solution with one piece each of red litmus, blue litmus and pH paper. Record your
findings.
4.
Dispose of the reacted metal and water by flushing down the drain with plenty of water. Place the paper towel in the
sink and completely wet it also. Then squeeze it out and place it in the metal can. Wash your hands with water and
dry thoroughly before proceeding with the next step.
5.
Repeat this procedure using each of the other metals listed on the data chart. NOTE: Ask your instructor to
demonstrate the reaction of potassium with water.
6.
You may have noticed an effervescent reaction in several of the above reactions, indicating a gas being produced. In
order to investigate the nature of this gas, you will collect a small sample as follows. Fill the beaker nearly full of tap
water. Fill an 18 mm X 150 mm test tube completely with water and cover the end with your thumb. Invert the test
tube in the beaker and then remove your thumb while keeping the test tube upright and full of water. Pour out about
one third of the water from the beaker. Drop a piece of calcium into the beaker and immediately place the mouth of
the test tube over the calcium. Allow gas to bubble into the test tube until it is one third full of gas, then lift it quickly
out of the beaker allowing the water to drain out. Set the test tube, mouth down on the desk. Now light a wooden
splint. Lift the test tube up and tilt it on a 45° angle and insert the burning splint inside the mouth. Record the result.
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
COMMON LABORATORY IDENTIFICATION TESTS
Litmus test: Litmus paper Blue in Basic (or alkaline) solutions and reD in aciD
pH paper Test: If the colour of the pH paper within 30 s of testing corresponds to a pH number less than 7, the
solution is acidic, if greater than 7, basic, and if equal to 7, neutral.
Burning splint test: If a colourless gas “pops” in the presence of a burning splint, the gas is probably HYDROGEN
gas.
Glowing splint test: If a glowing splint rekindles into a flame in the presence of a colourless, odourless gas, the gas is
most likely OXYGEN.
Lab #1- DATA SHEET NAME:___________________ LAB PARTNER ______________________
water
ELEMENT
lithium
magnesium
sodium
calcium
potassium
SYMBOL
FAMILY #
DESCRIPTION OF
ELEMENT (including
coating)
DESCRIPTION OF
REACTION WITH
WATER
REACTION TIME
(approx.)
ORDER OF
REACTIVITY
1= most/5= least
LITMUS TEST
red
LITMUS TEST
blue
pH paper test
colour/number
SPLINT TEST
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
EXPERIMENT 2
REACTION OF SELECTED ELEMENTS WITH DILUTE ACID (the search for patterns continues...)
In this experiment you will investigate the reactivity of magnesium, silicon and aluminum (elements from families
IIA, IIIA, and IVA) with dilute hydrochloric acid. Using your observations you will determine the order of reactivity of these
elements. Your conclusion should support the generalization made in experiment #1.
PRELAB: Before proceeding with this lab, read over the entire procedure carefully. Then write the PROBLEM and
HYPOTHESIS. Also prepare a blank data table. If you are not already familiar with the hazards of any of the chemicals you
will be using, read about these as well!
PRECAUTIONS: FACE SHIELDS AND APRONS MUST BE WORN WHILE DOING THIS LAB!!
PROBLEM: Write the problem to be investigated as a question. (HINT: your “problem” should be a single, coherent
question incorporating the ideas in the first two sentences in the introductory paragraph above. An unacceptable example of the
problem is “What is the reactivity of the elements magnesium, aluminum, and silicon?” as it is too simplistic.
HYPOTHESIS: Predict the order of reactivity of the elements (most reactive to least reactive) being investigated in this lab.
Support your prediction by citing evidence from the first lab. DO NOT START YOUR HYPOTHESIS WITH “I feel that
....” I think that ...”
PROCEDURE
1. Into each of three clean test tubes (18 mm x 150 mm) measure out 5.0 mL of dilute (approx. 3 mol/L) hydrochloric acid.
Place the test tubes in a test tube rack.
2.
On small squares of paper towel obtain from your instructor small quantities of each of the following elements: aluminum,
silicon, and magnesium. Record an accurate, concise description (colour, lustre form) of each on your data sheet.
3.
Obtain two wooden splints and arrange for someone to set up and light a Bunsen burner in your area. There is no need for
and in fact should not be a Bunsen burner for every lab partner pair. CAUTION: THE FLAME OF A BUNSEN
BURNER IS ALMOST COLOURLESS-KEEP WELL BACK. Be prepared to light the splint on short notice.
4.
Carefully drop the silicon into one of the test tubes of hydrochloric acid. Observe periodically over a 15 min. period and
record whether any reaction occurs. If effervescence is observed, test the resulting gas by inserting a burning splint just
inside the mouth of the test tube.
5.
Repeat procedure 4 using aluminum instead of silicon. (HINT: if some effervescence is observed place a piece of
masking tape over the mouth of the test tube for several minutes before testing with the splint.)
6.
While allowing the silicon and aluminum to react, prepare a splint ready to light. Insert the magnesium into the 3rd test
tube and observe. Does the test tube feel warmer as the reaction proceeds? Test with a burning splint just before the
magnesium completely disappears.
DISCARDING CHEMICALS:
ALUMINUM: The reaction with aluminum may become quite vigorous after a while. To slow this reaction down, carefully
pour the contents of the test tube into a small beaker half filled with water. Then place a piece of paper towel in the sink (not
over the drain). Carefully pour the contents of the beaker onto the paper towel. Rinse the remaining aluminum residue in the
test tube with water and pour out onto the paper towel. Allow the water to drain away. Then discard the wet paper towel with
the aluminum residue into the large metal waste container.
SILICON: Carefully pour ( without disturbing the solid) the acid from the test tube into the designated waste container in the
fume hood. Add some water to the test tube to rinse the silicon. Pour off the water into the sink. Then dump the solid contents
onto a piece of paper towel in the sink. Collect and return to the container designated by your teacher.
MAGNESIUM: Into the waste container in the fume hood.
CONCLUSION: Use paragraph style and complete sentence form. Include all of the following :
-a brief summary of the reactions observed. (2-3 concise sentences) including the significance of the splint test
-the order of reactivity of these elements with dilute hydrochloric acid (1 sentence)
-was this order consistent with your prediction?
-was your hypothesis upheld?
-a general statement about the order of reactivity of elements in families IA through IVA
-a general statement about the gaseous product of the reaction of metals with acids.
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
SAMPLE DATA CHART (prepare a 1 page chart for recording your observations):
ELEMENT
silicon
aluminum
magnesium
SYMBOL
FAMILY #
Description of element
Description of reaction
with hydrochloric acid
Reaction time
Splint test
Order of reactivity
EXPERIMENT 3: THE REACTION OF ELEMENTS WITH OXYGEN
In this experiment you will investigate the reaction of a number of both metallic and non-metallic elements with
oxygen. The results of these reactions should permit you to extend or modify some of the generalizations regarding reactivity
trends you made in the previous two experiments. This is the main objective of the lab. A secondary result of this experiment
is that it will allow you to learn something about the nature of acidic and basic solutions.
PRELAB: Read over the entire procedure and begin your write-up by writing the PROBLEM (as a question please), the
HYPOTHESIS and by preparing a blank, full page DATA TABLE. (see sample data table below)
PROBLEM: In a concise, coherent question, phrase the problem (main objective) in this lab.
HYPOTHESES: Predict whether the trend toward decreasing reactivity from left to right will be supported or not and cite
scientific evidence to support your prediction (give your reason). Also, will the rend toward increasing reactivity down the
family be supported or not? Cite scientific evidence.
DATA: (make your own full page version of this chart) Keep it all on one page!
Description
Result of splint test
Oxygen
ELEMENT
sodium
phosphorus
silicon
sulfur
carbon
magnesium
symbol/family
Description of element
metal or nonmetal
Description of combustion
reaction in AIR *
Description of combustion
reaction in OXYGEN
Product description (before
adding water!)
Litmus test
pH test
Acidic/basic? nearly neutral?
*
Record intensity ( dull/bright/brilliant etc.) and colour of flame or glow
**
Record colour, odour ( if obvious) and form (smoke/powder/lump) of product.3.4
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SCH 3UK
1.
2.
3.
4.
5.
6.
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
PROCEDURE
Collect 2 bottles of oxygen from your teacher. Note that the bottles of oxygen are stored upright on the desk covered with a
glass plate that may not form an “air-tight” seal. What does that suggest about the density of pure oxygen as compared to
air?
Prepare 2-3 deflagrating spoons (a.k.a. combustion spoons) as follows: scrape out any loose residue, heat to “red hot” in
the tip of a well adjusted, hot Bunsen burner flame and hang over the edge of the sink to cool (about 3-5 min.)
Describe the appearance and odour of oxygen (remove cover for a few second and smell). Test oxygen by inserting a
glowing splint (light it , then blow it out) into the jar. Record.
CAUTION: DO NOT PERMIT THE HOT DEFLAGRATING SPOON TO TOUCH THE GLASS JAR AT ANY
TIME DURING THIS PROCEDURE!! Have your teacher place a pea-sized quantity of the element into one of the
dry, cool, clean deflagrating spoons. Record the description of the element. Then heat the spoon in the hot tip of the
burner flame. Note when/how it changes form as you are heating. When the burner flame acquires a white-yellow-orange
tint (or other clue - see below) the element may be burning. Remove BRIEFLY from the flame to check for combustion.
IF it continues to glow/flame in air, then the following sequence of steps should be carried out by one person only in
quick succession:
-note the colour/intensity of the combustion in air (have your partner record it.)
-remove the glass plate from the mouth of a fresh bottle of oxygen.
-insert the spoon into the bottle. Do not touch the sides!
-slide the glass plate back over to cover the mouth as much as possible.
-note the colour/intensity of the combustion oxygen.
-allow reaction to go until flame/glow goes out.
If the metal is not burning (no glow or flame) calmly return it to the burner and repeat the procedure.
When the combustion is complete, with the lid still on, observe and record the appearance of the product (colourless
gas/white smoke/white powder/ etc...) in the glass jar.
Add tap water to the jar to a depth of about 1.0 cm. Remove the spoon, replace the glass plate with a stopper and shake
vigorously for about ten seconds to dissolve as much of the product as possible. Perform the Litmus and pH tests on each
solution. Record.
PLEASE NOTE:
SPECIAL INSTRUCTIONS for each of the elements listed on your data chart.
sodium - some sodium my be left in the spoon when the reaction appears to be over. When adding water the
reaction may BE VIOLENT. STAND AT ARM’S LENGTH!!
phosphorus -Do this reaction in the fume hood! remove from burner flame when you see smoke and
yellow-orange flame.
silicon - heat until spoon is “red-hot”
sulfur - Do this reaction in the fume hood! heat until sulfur melts to dark brown/black liquid, very hard to
detect flame in air.
carbon - heat until carbon has a dull red glow
magnesium - CAUTION - DO NOT LOOK DIRECTLY AT BURNING MAGNESIUM ONCE IT IS
IN THE GAS JAR!! Look out of the corner of your eye or take a “sweeping glance” the way you
might look at the sun. It is OK in air.
_____________________________________________________________________________________
_____________________________________________________________________________________
k;ln/ln
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
For the following sections, include all answers in the proper section in your lab report
CONCLUSIONS:
Use sentence and paragraph format. In every conclusion you write you should address/discuss the following points
(but do not use them as headings)
-brief summary of the important observations Which elements burned in oxygen? Describe how they
burned (flame/glow; intensity and colour; product). How did reactions in air compare with reactions in
pure oxygen: (try to keep it to 2-3 sentences)
-extent to which your hypothesis was upheld Describe the general reactivity pattern observed from left to
right. ( Did reactivity appear to decrease or increase consistently from left to right or did the trend appear to
change at some point?) Describe the general pattern observed down family IVB. (Did reactivity increase
or decrease down family IVB?) How did these findings compare with your predictions? Was your
hypothesis completely upheld, partially upheld, or totally incorrect according to the results of the lab?
-sources of error or uncertainty Mention briefly some of the sources of error (unavoidable problems)
encountered in this experiment (e.g. Are colour and intensity of flame alone reliable evidence on which to
base reactivity trends?).
-answer the question Answer the question you wrote under the heading “Problem” (hint: do not start with
“the answer to the question is ...”)
DISCUSSION: REGULARITIES AND TRENDS
Refer to the results of all three labs when answering these questions.
1. Identify the liquid in which lithium, sodium and potassium are stored. Why is it necessary to store these
elements in this liquid?
2. Which one of the elements sodium, silicon, or magnesium was the least reactive? Was this consistent with the
pattern of reactivity observed in experiments 1 and 2?
3. Elements to the right of the “zig-zag” staircase line of the periodic table are classified as non-metals; those to
the left are classified as metals. Classify silicon, phosphorus and sulfur.
4. Which of the three elements, silicon, sulfur or phosphorus was found to be least reactive? Do elements become
more or less reactive moving to the right of the “zig-zag” line?
5. Compare silicon and carbon. Both are members of family IVB. Which was more reactive?
6. The pattern of reactivity for non-metals in family IVB is generally true for all non-metals. Does reactivity
increase or decrease down non-metal families?
7. RECOPY and complete the following statements. Consult your experimental data as needed.
Metal oxides when dissolved in water form _____________ (acidic/basic) solutions.
Non-metal oxides when dissolved in water form _________(acidic/basic) solutions.
8. On a blank periodic table fill in (in pencil) the following details:
- the line dividing metals and non-metals (label which is which)
-the symbols of the elements investigated in this unit
- the general reactivity tends discovered in this unit using arrows. the arrow begins at the least reactive element
and the head points toward the most reactive element. Your chart should have a total of four arrows on it. 1
pointing down, 1 pointing up, 1 pointing to the left and 1 pointing to the right.
9. Which of the three elements from Family IA (sodium, lithium, potassium) was the most reactive? Which was
the least reactive?
10. State the apparent order of reactivity as one proceeds down Family IA, i.e. does the reactivity increase or
decrease down the family.
11. Which element from Family IIA, magnesium or calcium was more reactive? What is the apparent order of
reactivity down Family IIA?
12. Compare adjacent Family IA and Family IIA elements investigated. Which is more reactive, magnesium or
sodium? calcium or potassium? In general which family of elements is more reactive, Family IA or Family
IIA?
13. Make a prediction about the apparent order of reactivity as one proceeds from left to right across the periodic
table.
14. Predict several observations you might expect to make if you were to drop a piece of barium into a beaker of
water.
15. Predict several observations you might expect to make if you were to drop a piece of cesium into a beaker of
water.
16. What gas is produced when metals react with water?
17. What type of solution (acidic or basic) is formed when metals react with water?
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
APPLICATION QUESTIONS
1. Predict 5 observations you would expect to make if you dropped a piece of rubidium metal into a beaker of
water.
2. Predict what you would expect to see if you dropped a piece of beryllium into a beaker of water.
3. Which one of each of the following pairs of elements should be more reactive:
a) iodine or chlorine
b) selenium or sulfur
c) rubidium or strontium
d) francium or barium
4. An unknown element reacts with oxygen to form a colourless gas. This gas is then shaken with water to
dissolve it. When the resulting solution is tested with pH paper a pH of 10 is recorded. Is this element a metal
or a non-metal? Cite (give) experimental evidence to justify your answer.
ASSESSMENT:
Attached Rubric
Please note all the components (parts of the lab report must be complete and included.
A sample lab report file is also attached and an electronic copy is found in the class folder on the
website.
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SCH 3UK
UNIT 1 FORMAL LAB: PATTERNS IN THE PERIODIC TABLE
Grade 11 CHEMISTRY – Laboratory Report Assessment Rubric
Kingston Collegiate & V.I.
/50
OVERALL MARK:
Section
Specific Element
Description for Level 4
What was done
By what method
What the main results were
Conclusions drawn from these results
Communication of information and ideas,
in a scientific report format
Communicates a summary of experiment
information and results in a thoughtful,
well-organized way.
Statement of the purpose of the experiment
Review of pertinent literature (including references)
of the theory underlying the experiment and the
procedure
A hypothesis, or prediction, about the results
Communication of information and ideas,
in a scientific report format
Reference the method used in laboratory
manual/handout
note any changes made
Communication of information and ideas,
in a scientific report format
•
Describes contents of paper. Name, date, etc..
Abstract
(1 paragraph
max.)
•
•
•
•
•
•

•
Method
•
Results/
Observations
Data Tables
•
Titles
•
Column headings (including units)
•
A clear and accurate display of data
Analysis
Graphs
•
Appropriate axes and labels and units
•
A clear and accurate display of trends
Calculations

Complete and comprehensive calculations and units

where appropriate include error
Tables
•
Appropriate Title and labels with units
•
Calculated data



Statement of results as evidence for or against
hypothesis – draw on specific and representative
results (use numbers)
Explanation of results – with reference to data tables
and graphs (use numbers you found to explain results
argument)
Revisit theory from introduction and connect with
your results
Discuss sources of error
explain unusual results due to error
experimental modifications to reduce error for next
time
Conclusion
Application of your results to the real world
Possible Future Studies
References


Within text – proper format (APA)
Reference List – proper format (APA)
Overall
Impression




Spelling and writing relatively error free
Neat and complete and organized
Logic and coherence of report as a whole
Irrelevant theory deduction

How you carried out the experiment: safety,
cleanliness, safe use of laboratory equipment,
technical skills in the lab
•
•
•
Discussion
•
-
Experiment
Execution
Date:__________________________
Curriculum Expectations
Title
Introduction
Name:_____________________________
Use of scientific terminology, including
symbols, units, significant digits
Use of various forms of communication,
including diagrams, tables, graphs – with
correct labels, headings, titles, etc.
Understanding of concepts, principles,
laws, and theories
Knowledge of facts and terms
Use of various forms of communication,
including diagrams, tables, graphs – with
correct labels, headings, titles, etc.
Knowledge of facts and terms
Understanding of relationships between
concepts
Proposing further courses of action,
and/or making connections among
science, technology, society, and the
environment
Communication of information and ideas,
in a scientific report format
Communication of information and ideas,
in a scientific report format, including
spelling and grammar
Use of scientific terminology, including
symbols, units, significant digits
Skills and strategies of scientific inquiry:
designing, planning, and performing
experiments
Technical skills in laboratory techniques
Safe and correct: use of tools, equipment
and materials; disposal of materials;
cleanup
Communicates all aspects of the
introduction in a clear, thoughtful, wellorganized way. used proper scientific
language and conventions
Communicates all aspects of the method
in a clear, thoughtful, well-organized
way. used proper scientific language and
conventions.
IN TEXT CITATION OF THE
METHOD IF PROVIDED AT THE END.
Tables are used where appropriate and all
units and titles are provided. Tables are
introduced and described. Qualitative
observations are included. Potential areas
for ERROR are noted.
Graphs and Tables are used where
appropriate and included graph and axes
titles and units, introduction before the
graph in the text, and description in italics
following the graph.
Sample calculation including the general
formula used are shown and the exact
data used in the sample is explained…
“data to show the sample calculation is
used from trial one on observation table
2”
Statement of the results is clear and refers
to the hypothesis.
Correct scientific terms are used to
communicate results and EXPLAIN the
results.
Error (systematic and Random error) and
the effects that the error would have on
the results is discussed.
Next steps and applications to society of
the results or concepts examined in the
lab are discussed with sources where
appropriate.
References are made IN TEXT and
include a works cited page
Communication is almost completely free
of error in spelling and grammar. It is
completely free of error of scientific
terminology, symbols, units and
significant digits
Experiment was designed appropriately
where applicable to assessment.
Lab was carried out free from safety
issues, reminders from teachers and the
lab station was properly set up and put
away to leave a clean work area.
Materials were always treated properly
and disposed of correctly.
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