I.P.S. ⓕⓘⓡⓢⓣ ⓠⓤⓘⓩ

Safety, Lab: Reaction in a Bag, Lab: Heating Baking Soda

Safety

◇ goggles must be on until Mr. Leeds says to put them away

◇ nurse: 2828

◇ fire extinguisher, fire blanket, eye wash/shower

◇ never taste chemicals

◇ always waft liquids

◇ never waft solids or powders

◇ avoid touching chemicals

◇ always wash hands

◇ if chemicals touch skin; flush skin with water and notify Mr. Leeds

◇ hot glass and cold glass look the same

◇ roll up sleeves

◇ put long hair in a bun

◇ do not look down into a test tube/beaker while it's being heated

◇ make sure burner is capped and flame is out when done

◇ clean up area and materials completely

Lab: Reaction in the Bag

Purpose: to record the observations that occur when multiple chemical substances are combined and to use my observations to understand the reactions of the chemicals.


Experimental Error: hole in the bag- you wouldn't know that a gas was produced.


Important things to know:

Hot- A + liquid (Exothermic Reaction)

Cold- B + liquid (Endothermic Reaction)

Gas- B + A + liquid


Red Liquid:

▻ phenol red

▻ used as a ph indicator

▻ below 7 turns yellow

▻ above 8 turns pink


Ph Scale:

▻ measures acidity

▻ goes from 0-14

▻ 0-7-14 9 (acid, neutral, alkaline)

▻ lemon juice- 1.5

▻ turns 10


2 Solids:

1. calcium chloride (calcium-chloride)

▻ acidic (ph-6)

▻ hydrotropic- attracted/absorbs water

▻ uses- canned vegetables (keeps them from getting mushy)

▻ electrolyte- in sports drinks

▻ flavors- pickles (salty)


2. sodium bicarbonate (baking soda)

▻ not acidic (ph 8.45)

▻ uses: baking, laundry detergent, toothpaste


Lab: Heating Baking Soda

Purpose: to observe and record the reaction that occurs when baking soda is heated.



Control group: unheated, because we didn't put anything in it.


Experimental group: heated, because once we added heat, it turns into an experiment


Indicator: tea, it indicates that the heated baking soda has changed, and that it isn't baking soda anymore.


Variable: (something you try to measure)

1. independent variable- (causes a change in the depended) it's the temperature (heat/fire)

2. dependent variable- the color of the tea


Control factor: (factors we control) same type of tea, same amount of baking soda, same amount of tea, same stirring time, same size test tubes


Experimental Errors:

▻ hole int he tubing- gas will escape, and you wound't notice gas being created by the baking soda (won't see the bottle with gas)

▻ stopper not snuggly- won't see the bottle with gas

▻ stirring rod not cleaned properly before you begin- contaminate


Extra Question:

▻ Is the amount of condensation that forms at the top of the heated test tube more or less than the amount of baking soda being heated? Explain your answer.

Less (or equal to) because the condensation comes form the baking soda. It can't produce more than itself.


Box Question #1:

▻ Why do you think baking soda is used in baking?

When you heat baking soda, it releases gas and helps dough/batter to rise. (cupcakes, muffins, bread, etc.)



Lab: 1.2 Volume Notes

Unit measurement- cm3 (cubic centimeter)


Standard unit of length- meter (m)


◇ 1 centimeter (1cm) = 0.01 m


◇ 100 centimeters = 1m


Volume of Liquids:

▻ use a graduated cylinder to measure volume

* always check the intervals or scale

▻ units- millimeters (mL) or cm3

* 1mL = 1cm3

Single Pan Balance Notes:

▻ Check that pan is clean and dry

▻ Always "zero" balance before each massing

▸ Push all riders to zero (left)

▸ use adjustment knob