MC

MC	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

Jenna suspects that she can affect the rate of the chemical change that takes place when vinegar is combined with baking soda to make her model volcano erupt at different rates. The best way for her to know for sure would be toÉ

ask her science teacher who does it all of the time in the laboratory at school.
experiment with several variables such as crushing, heating, stirring, cooling etc.
read about it in her textbook, under chemical reactions.
Look it up on the internet to see what Bill Nye suggests.

Correct Answer: b

MC	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

A pile of snow melts faster than the same amount of block ice. Which factor listed below contributes the LEAST to the rate of melting?

a. surface area

b. temperature

c. exposure to direct light

d. the initial volume of snow and ice

Correct Answer: d

MC	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

The following results were collected during 3 experiments that involved dissolving sugar in water.

Experiment #	Amount of Sugar	Amount of Water	Temperature	Particle Size	Minutes to Dissolve
1a	5g	20mL	30¡	small	2:00
1b	5g	20mL	50¡	small	1:00
2a	5g	20mL	30¡	large	3:00
2b	5g	20mL	30¡	small	2:00
3a	1g	20mL	30¡	small	1:30
3b	5g	20mL	30¡	small	2:00

1. Which variable was tested in experiment #2?

a. Amount of sugar

b. Amount of water

c. Particle size

d. Time to dissolve

2. What did experiment #1 show about dissolving sugar?

a. 5g of sugar will dissolve slower than 1g sugar

b. Raising temperature increases speed of dissolving

c. Large particles dissolve slower than small particles

d. There is no reason why sugar dissolves at different rates

3. Which variable was not controlled in experiment #3?

a. Amount of sugar

b. Amount of water

c. Temperature

d. Time to dissolve

Correct Answers:

1. c

2. b

3. a

MC	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

What is one way the development of synthetic fibers has affected the clothing we wear?

a. synthetics are waterproof

b. synthetics have more stretch

c. natural fibers wear longer

d. synthetics donÕt burn

Correct Answer: b

MC	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

In 1988 Pons and Fleishman were working on a concept called cold fusion. Cold fusion, if correct, would be a revolutionary source of energy. The entire world would change if this idea could be proven! Because of immense pressure to be the first to discover cold fusion, Pons and Fleishman got some results and without verifying these results announced the discovery of cold fusion. It turned out to be wrong. Why did Pons and Fleishman abandon the scientific process that requires duplication of experiments and announce their discovery early?

a. The scientists who proved cold fusion would be wealthy and world renowned and so would their sponsors.

b. Cold fusion was so important there seemed to be no reason to wait.

c. Cold fusion just had to work because the theory was perfect.

d. Once a theory has been tested it is accepted as truth.

Correct Answer: a

I	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

Acid rain is found in parts of the country where there are many cars and power plants. Water in the form of rain is chemically combined with sulfur dioxide and oxygen to create sulfuric acid, which becomes acid rain.

1. In the reaction above, which substances are considered the reactants?

a. sulfur dioxide, oxygen, and water

b. oxygen, water, and sulfuric acid

c. water, sulfuric acid and sulfur dioxide

d. sulfuric acid, sulfur dioxide, and oxygen

2. In the reaction above, which substance is considered the product of the reaction?

a. sulfur dioxide

b. water

c. oxygen

d. sulfuric acid

Correct Answer:

1. a

2. d

E	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

Briefly describe each of the following chemical reactions and clearly explain how they are similar.

1. Rust

2. Fire

3. Respiration

4. Photosynthesis

Scoring Guide:

4 pts Clearly describes each reaction and identifies two properties they share. (Includes both a physical and chemical equation).

3 pts Describes each reaction and identifies one property they share.

2 pts Describes each reaction.

1 pts Describes two or more reactions.

E	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

For a chemical reaction to occur, molecules must come in contact with each other. Digestion of food involves a chemical reaction. Hypothesize and describe four ways that the rate at which digestion occurs can be increased and give examples of each.

Scoring Guide: (10 points possible)

4 pts Mentions high concentration of reactants, increasing surface area, temperature, and catalysts and gives valid examples of each that apply to the digestion of food.

3 pts Mentions only three ways of increasing reaction rates or misses one example.

2 pts Mentions only two ways of increasing reaction rates or supplies weak examples.

1 pts Mentions only one way of increasing reaction rates and examples are unrelated.

P	*8^th Grade Integrated Science*	*Standard:* 01
*Objective:* 04. Identify the observable features of chemical reactions.
*ILO:*

Changing States of Matter

TEACHER INFORMATION

Materials needed: Ice cubes, beaker, thermometer, heat source, watch, salt.

Background information: In this activity students will observe ice as it melts and record temperature changes. They will determine at what temperature ice changes to a liquid and the temperature at which water changes to the gas phase. They will make a table that displays the data they collect and answer thought questions about what happens. They will then add salt to water, predict what will happen, then collect data on temperature change until the water boils and finally try to explain what happens.

Scoring Guide:

Accurately record temperature changes 10%

Graph data correctly 30%

Answer questions correctly 60%

Answers to questions:

1. the temperature stayed at 0¡C until the ice was gone.

2. the melting point of water is 0¡C

3. The temperature stayed at about 100¡C during that time. Note: the temperature will vary slightly on the boiling point depending on the elevation above sea level. Air pressure affects the temperature at which a substance changes phases

4. The temperature remains the same during a phase change. Water remains at 0¡C when changing from solid to liquid and stays at 100¡C while changing from liquid to a gas.

5. The water used the heat to change its phase and little or no change in temperature occurred during either phase change.

6. predictions will vary

Changing States of Matter

STUDENT WORKSHEET

Directions: In this activity, you will observe ice as it melts and record the temperature changes. From the temperature changes, you will determine at what point the ice changes from the solid phase to liquid, and continue heating until it is the gas phase.

Place one ice cube in the beaker, set up the thermometer so it is close to the ice cube but not touching it or the bottom of the beaker. Gently warm the beaker until water forms from the ice cube. If the ice is completely melted, add another ice cube. The thermometer should be in the melted ice water. Time begins at that point as "0". Continue heating the beaker. Record the temperature every 30 sec. and continue heating for 3 minutes after it begins to boil.

Data Table

Time	Temperature	Time	Temperature
0.5		5.5
1		6
1.5		6.5
2		7
2.5		7.5
3		8
3.5		8.5
4		9
4.5		9.5
5		10

Make a graph charting the temperature change against the time.