science 24 chapter 2 notes.notebook - weebly · 3. notes on chemical reactions 4. assignments...

Science 24 Chapter 2 Notes.notebook February 20, 2015

Science 24: Day 10

1. Review chemical vs. physical reactions

2. Chemical reactions video

3. Useful chemical reactions research assignment


https://www.youtube.com/watch?v=FofPjj7v414

Which reaction was your favorite?

What kinds of things did you observe?

What did all the chemical reactions have in common?

https://www.youtube.com/watch?v=fofpjj7v414


Baking a cake

Processing

films

Dying hair

Driving a car

Fruit ripening

Rust

Batteries

Teeth whiteners

Pick one of the chemical reactions on the left (or come up with your own).

1) Research how the chemical reaction works.

2) Either type or write a paragraph to explain how it works IN DETAIL! Include

any important chemical names AND how the

reaction occurs.

3) Present your research to the class (explain what

you found out!) Marked out of 5:

5 a thorough and accurate explanation was provided

4 the explanation was mostly accurate and thorough

3 the explanation was somewhat accurate and thorough

2 the explanation was severely lacking either in accuracy or thoroughness

1 the explanation was severely lacking in accuracy and explanation

0 no explanation of the chemical reaction was provided


Science 24: Feb 18th

1. Review useful chemical reactions

2. Vinegar and baking soda demo

3. Notes on chemical reactions

4. Assignments


2.2: Changes That Occur

Chemical reaction: substances you start with are not the same as the substances you end withIndicators of chemical change:

‐ gases may be given off or new solids formed

‐ colors may change‐ odours may be given off


Introduction to Word Equations

‐ Word equations are representations of a chemical reaction.

Reactants ‐> Products

‐ If there is more than one reactant, they are separated with a plus sign. ‐ If there is more than one product, they are separated with a plus sign. ‐ The reactants and products are separated with an arrow.

Reactant 1 + Reactant 2 ‐‐> Product 1 + Product 2

Vinegar and baking soda example:


‐ In the vinegar, baking soda, and candle demonstration, we saw 2 types of chemical reactions:1) Combustion: a fuel burns in oxygen

ex.

2) Neutralization: an acid is added to a base to produce water and a salt

ex.



1. Finish lesson on word equations

2. Word equations and combustion/

neutralization worksheets

3. Lesson on evidence of chemical change

and energy of chemical changes

3. Demo

4. Assignments


Identify if the following is neutralization or combustion reaction:

1) magnesium hydroxide + hydrochloric acid ‐‐> magnesium chloride + water

2) methane + oxygen ‐‐> carbon dioxide + water + heat

3) butane + oxygen ‐‐> carbon dioxide + water + heat

4) calcium hydroxide + hydrobromic acid ‐‐> calcium bromide + water


How do we write word equations from sentences?

ex. Sodium bicarbonate and acetic acid reacted to produce carbon dioxide, water, sodium ions, and acetate ions


Assignment:

1) Word equation sheet

2) Combustion or neutralization sheet


2.3 Evidence That Change Has Occurred

1) Different colour produced2) Odour produced3) Bubbles appear 4) Precipitate (solid formed during chemical reaction)5) Energy is given off or taken in



1. Mind maps on reactions

2. Lesson on energy of chemical changes

3. Demo

4. Assignments


Make a Mind Map of the following words:

Chemical change

Physical change

Neutralization

Combustion

Word Equation


2.4 Energy and Chemical Reactions

Energy Change obvious or unnoticeable production or absorption of a form of energy as part of chemical reaction

Examples: Is it absorption or production of energy?

1) Fireworks

2) Rusting

3) Gasoline

4) Baking bread


Exothermic processes Endothermic processes

making ice cubes melting ice cubes

formation of snow in clouds conversion of frost to water vapor

condensation of rain from water vapor evaporation of water

a candle flame forming a cation from an atom in the gas phase

mixing sodium sulfite and bleachbaking bread

rusting iron cooking an egg

burning sugar producing sugar by photosynthesis

forming ion pairs separating ion pairs

combining atoms to make a gas molecule splitting a gas molecule apart

mixing strong acids and water mixing water and ammonium nitrate

nuclear fission melting solid salts


Reactions in chemistry are described as endothermic and exothermic, not as absorption or production of heat.

Endothermic reaction: A reaction that absorbs energy. Ex) photosynthesis

carbon dioxide + water + energy > glucose + oxygen

Exothermic reaction: A reaction that produces energy. Ex) metabolism

fats + carbohydrates > heat + energy


Assignments:

1) Questions p. 37 #132) Endothermic and Exothermic Reactions Sheet

science 24 chapter 2 notes.notebook - weebly · 3. notes on chemical reactions 4. assignments...

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