critical thinking matter i i

Unit 1: States of Matter/Physical and Chemical Changes

Learning objectives;

to understand three states of matter

to distinguish the properties of three states of matter

to identify physical and chemical properties of substances

to distinguish characteristics of physical and chemical changes

Unit 1: Worksheet

1. Define ‘Matter’.

___________________________________________________________

2. Identify three states of matter.

i)____________ ii)____________ iii)____________

3. The box at left represents the atoms of aluminum (.) in the solid state.

Represent the same atoms in the liquid state in the box at right.

solid state liquid state

4. Draw the diagram of CO2 in gaseous state below.

CO2 =

5. Identify which of the following represents a compound. ____

i) ii)

Explain your reasoning.

6. Classify each of the following as pure substance or mixture.

i) ii)


7. Describe the change of states of water when you boil 50.0 mL of water in

a tightly closed container.

After cooling the water to the room temperature, the resulting volume of

water was measured. Would you expect to see the change of the volume

of water? Explain your answer.

8. The following represents the liquid state of water (H2O).

a) Which of the following diagrams best represents water (H2O)

molecules after liquid water was heated to vaporize? _______

i) ii) iii)

Is vaporization physical or chemical change?_________


b) Water (H2O) can be decomposed into hydrogen gas (H2) and

oxygen gas (O2) by the process called electrolysis.

Draw the diagram ii) of hydrogen gas and oxygen gas.

Electrolysis

i) ii)

Is an electrolysis physical or chemical change? ___________


9. Which of the following indicates chemical change? _______

+i)

ii)+

Explain why.

10. State the Law of Conservation of Mass in your own words.

If you dissolve 3.00 grams of sugar in 50.0 g of water, what would be the

total mass of the mixture of sugar and water?

When you dissolve 3.00 grams of Alka-Selzer in 50.0 g of water, the total

mass of the mixture turned out to be less than 53.0 grams. Explain why.

Does the process of dissolving Alka-Selzer in water disobey the Law of

Conservation of Mass? Explain.

11. Sample of solid iodine was placed in a sealed vacuum tube. The weight of the

tube with iodine solid was 12.5 grams. When the tube was

heated, it was filled with iodine gas.

iodine solid (I2)

iodine gas (I2)

Heating

a) What is the name of the change from solid to gas? ____________

b) Is this change physical or chemical? _________

Explain why.

c) Which of the following statements is correct? _____

i) The weight of the tube after heating is less than 12.5 grams

because a gas weighs less than a solid.

ii) The weight of the tube before or after heating is the same

because mass is conserved during the change.

d) Represent the change of solid iodine to gaseous iodine by depicting

several iodine molecules as shown below.

= iodine (I2)

heating

solid iodine gaseous iodine

12. Mixture of substances A and B was separated by filtration process shown

below.

Filter paper

beaker

Funnel

glass rod

Filter paper

beaker

Funnel

filtration after filtration

a) Discuss whether filtration is a physical or chemical process.

b) Which of the following represents water? _____

i) ii) iii) unable to determine

13. Substance A and substance B were mixed in a beaker. After stirring the

mixture vigorously, it was divided into two equal portions. To separate

the substance A and B for each portion, filtration method was used and the

following results were obtained.

Mass of substance A Mass of substance B

Portion I 12.5 g 23.3 g

Portion II 16.7 g 19.1 g

a) Discuss whether mixing A and B is a physical or a chemical process.

b) Is the mixture homogeneous or heterogeneous? _____________


Unit 2: Measurements


to read and record measurements with correct number of significant figures

to use correct metric units with the quantity being measured

Unit 2: Worksheet

For each of the following, record the value of the measurement with correct units.

A. Measurement of length

Ruler (in cm) Measurement

B. Measurement of volume

Graduated cylinder (in mL)

scale

reading ________

uncertainty

________

scale

reading ________

uncertainty

________

scale

reading ________

uncertainty

________

9 10 11

Beaker (in mL) Buret (in mL)

scale

reading ________

uncertainty

________

scale

reading ________

uncertainty

________

Unit 3: Double Replacement Reaction


to understand the general pattern of double replacement reactions.

to predict whether the reactions occur

to write complete balanced chemical (or formula) equations.

Unit 3: Worksheet

1. Write balanced chemical equations for the following reactions.

A. Precipitation Reaction

Cl-

Na+

Na+

Cl-

Ag+

NO3-

Ag+

Na+

Cl-

Ag+

NO3- NO3

-

NO3-

Na+

Na+

NO3-

Na+

NO3-

+

AgCl(s)AgCl(s)AgCl(s)

Chemical equation:

________________________________________________________________________

B. Gas Formation Reaction

CO32-

Na+

Na+

Na+

CO32-

CO32-

H+

H+

H+

H+

Cl-

Cl-

Cl-

H+

H+

Cl-Cl

-

Cl-

Na+

Na+

Na+

Cl-

Na+

Na+

CO2(g)

Na+

Cl-

Cl-

CO2(g)

Cl-

Na+

Cl-

Na+

CO2(g)

Na+

Cl-+

Chemical equation:

________________________________________________________________________

C. Acid-Base Neutralization

Na+ Na

+

Cl-

H+

H+

Cl-

Cl-

Na+

H+

Cl-

H+Na

+ Cl-

Na+

Na+ Cl

-

Cl-

Na+

Na+

Cl-

+OH-

OH- OH

-

OH-

OH-

Chemical equation:

________________________________________________________________________

2. Draw the diagram for each of the following double replacement reactions after

writing complete balanced equations and classify each of the reactions as

precipitation, gas formation, or acid-base neutralization reaction.

A. Chemical equation: KOH(aq) + H2SO4(aq) �

+

Classification of the reaction:_________________

B. Chemical equation: Na2SO3(aq) + HCl(aq) �

+


C. Chemical equation: BaCl2(aq) + KNO3(aq)

+


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