Focus Plan
Texarkana Independent School District
PLAN CODE:
WRITER:
IPC – 5th six weeks, Biology – 1st
six weeks, Chemistry – 4th six
weeks
L. Petty
COURSE/SUBJECT:
11th grade science
GRADE(S):
11th
TIME ALLOTTED
FOR INSTRUCTION:
1 hour
GRADING
PERIOD:
TITLE:
Polar Water
LESSON TOPIC:
Solubility in polar and nonpolar solvents.
TAKS OBJECTIVE:
Objective 4
The student will demonstrate an understanding of the structures and properties
of matter.
11.9 The student knows how solution chemistry is a part of everyday life. The
student is expected to:
(A) relate the structure of water to its function [as the universal solvent].
Objective 1: The student will demonstrate an understanding of the nature of
science.
11.1 The student, for at least 40% of instructional time, conducts field and
laboratory investigations using safe, environmentally appropriate, and
ethical practices. The student is expected to:
(A) demonstrate safe practices during field and laboratory investigations
11.2 The student uses scientific methods during field and laboratory
investigations. The student is expected to:
(A) plan and implement investigative procedures including asking
questions, formulating testable hypotheses, and selecting equipment
and technology
(B) collect data and make measurements with precision
(C) organize, analyze, evaluate, make inferences, and predict trends from
data
(D) communicate valid conclusions
FOCUS TEKS AND STUDENT
EXPECTATION:
SUPPORTING TEKS AND
STUDENT EXPECTATIONS:
CONCEPTS
Universal
ENDURING UNDERSTANDINGS/GENERALIZATIONS/PRINCIPLES
The student will understand that
Solubility is a universal necessity.
Life
Living things cannot survive without certain compounds.
Solubility
These necessary compounds are soluble so they can be transported through the
body.
Some compounds are soluble in water and some are only soluble in other types of
solvents.
The polarity of water allows more types of substances to dissolve in water than in
any other solvent.
Solvents
Polarity
I.
SEQUENCE OF ACTIVITIES (INSTRUCTIONAL STRATEGIES)
A.
Focus/connections/anticipatory set
When students are seated, show a short clip of blood rushing through the veins or arteries. This can be found
on any video dealing with the circulatory system. When the video has played for several minutes, turn it off
and explain to students that the blood is necessary to transport materials throughout the body. If this
transportation didn’t work, they would not live. In order to get through the body, however, these materials
must first dissolve in the blood; they must be soluble. Explain that this lab deals with the solubility of
substances.
B.
Instructional activities
(demonstrations, lectures, examples, hands-on experiences, role play, active learning experience, art,
music, modeling, discussion, reading, listening, viewing, etc.)
1. Lecture
Go over Transparency master – Vocabulary
Go over Transparency master – Explaining Polarity
C.
Guided activity or strategy
Have a water molecule and a salt molecule (either with paper models or wood models) to demonstrate how a
polar solvent helps pull a polar molecule apart. Hold the oxygen side of the water (negative) next to the
sodium (positive side of the salt) and explain that the negative and positive charges form a slight attraction.
This attraction can interfere with the attraction between the original molecules and cause them to dissolve.
D.
Accommodations/modifications
Students requiring accommodations may be given copies of both transparency masters and may be assigned a
peer tutor.
E.
Enrichment
Students requiring enrichment may define the vocabulary prior to class for a grade and may be assigned as a
peer tutor.
II.
STUDENT PERFORMANCE
A.
Description
Students should complete Lab – Polar Water.
B.
Accommodations/modifications
Students requiring accommodations may be assigned a peer tutor.
C.
Enrichment
Students requiring enrichment should be assigned as a peer tutor.
III.
ASSESSMENT OF ACTIVITIES
A.
Description
Complete Lab Worksheet – Polar Water
B.
Rubrics/grading criteria
Deduct 3 points for each data table box answered incorrectly or left blank. Each part of each question is
worth 5 points (25 total).
C.
Accommodations/modifications
None needed.
D.
Enrichment
Students requiring enrichment should be asked to differentiate between miscible and soluble. They may also
be given more substances to investigate or research to determine their solubility in water. If more lab time is
desired, they may be given the assignment to test the solubilities in another substance like alcohol.
E.
Sample discussion questions
1.
2.
3.
IV.
Which substance was the most soluble in water? This will depend on your lab, but will often be sucrose
or ethanol.
Which substance was the least soluble in water? Again, this will depend on the lab, but will often be
glycerol or kerosene.
Alcohol is a nonpolar molecule, which types of substances should dissolve in alcohol? The rule for
dissolving is generally “like dissolves like”, so alcohol should dissolve nonpolar substances.
TAKS PREPARATION
A.
Transition to TAKS context
1. The polar structure of water molecules enables it to act as an effective solvent for ionic compounds. Why
does this occur?
(a) The polar structure of water molecules reduces the electrostatic attraction between positively charged
ions and negatively charged ions in the solute.
(b) The polar structure of water molecules increases the electrostatic attraction between positively charged
ions and negatively charged ions in the solute.
(c) The polar structure of water molecules is weakened by positively charged ions and negatively charged
ions in the solute.
(d) The polar structure of water molecules is strengthened by positively charged ions and negatively
charged ions in the solute.
2. Water is an effective solvent for ionic compounds because the polar structure of its molecules reduces the
electrostatic attraction between ions having positive charges and negative charges. The ions become
hydrated, or surrounded by water molecules. Why do the ions remain separate rather than recombining to
come out of solution?
(a) The ionic charges are distributed within a smaller structure.
(b) The ionic charges are concentrated within a smaller structure.
(c) The ionic charges are distributed within a larger structure.
(d) The ionic charges are concentrated within a larger structure.
B.
Sample TAKS questions
Spring 2003
1. If the properties of water were to change so that the solid form was denser than the liquid form, organisms
living in a cold pond environment would be less likely to survive because water would no longer ____.
(a) dissolve enough oxygen from the air
(b) produce solutions containing vital nutrients
(c) remain neutral, instead becoming highly acidic
(d) produce a floating insulating layer of ice
Spring 2004
2. Fish survive through severe winters because of the property of water that allows water to ____.
(a) form chemical bonds as it freezes, raising the water temperature below the ice
(b) increase in density while it freezes, dissolving more oxygen from the air
(c) expand when it freezes, creating a floating and insulating layer of ice
(d) precipitate vital nutrients when it freezes, increasing the food supply
V.
KEY VOCABULARY
insoluble
miscible
nonpolar
VI.
polar
solubility
soluble
RESOURCES
A.
Textbook – none needed.
B.
Supplementary materials/equipment
Transparency master – Explaining Polarity
Transparency master – Vocabulary
Instructor’s Copy - Vocabulary
Lab Instructions – Polar Water
Lab Worksheet – Polar Water
Instructor’s Copy – Polar Water
C.
VII.
Technology
FOLLOW UP ACTIVITIES
(reteaching, cross-curricular support, technology activities, next lesson in sequence, etc.)
A. Reteaching
Go over graded labs with students.
B. Next lesson in sequence
All subjects – solubility.
VIII.
TEACHER NOTES
Before lab:
1. Make sure all containers are properly labeled.
2. Make sure liquid chemicals are in dropper bottles.
3. Have a disposal container for the hexane and kerosene.
4. Caution students that the sample sizes used for solid chemicals must be the same or they will invalidate their lab
results.
During lab:
5. Make sure students are using small, even amounts of the solid chemicals.
6. Check their technique for “flicking”
7. Make sure students do not dump hexane and kerosene down the drain.