# THE EXAM

## Reaction in a Bag Study

Purpose: Record observations when multiple chemicals are combined and to understand the chemicals.

Lab safety: Wear goggles and aprons

Red liquid: Phenol Red "used to indicate Ph scale".

- 0-7 yellow

- 8-14 pink

Solid A= Calcium chloride also Hydro tropic and acidic

Solid B= Sodium Bicarbonate (Baking Soda)

Not Acidic

## Heating Baking Soda Study Guide

Purpose: Record what happens when Baking Soda is heated

Control factors: Same amount of tea, and the same amount of baking soda, Same size test tubes and same stirring time.

Color difference and Heated is usually darker.

Box Q: To release gas when heated.

1. Why do you think baking soda is used in baking?

Baking soda is used in baking to make the dough rise.

MAKE SURE YOU WEAR GOGGLES WHEN YOU USE A BURNER OR WORK WITH GASES.

Terms

Control Group: Unheated

Experimental Group: Heated

Indicator: Tea

Variable: Something you try to measure

Independent Variable: Causes change in temperature

## Volume Notes

Chemistry Experiment Goes Wrong For Teacher YouTube.

Unit of Measurement: CM3 (Cubic Centimeter)

Volume = L x W x H or "A x B x C"

Standard unit of length = meter (m)

1 centimeter (1cm) = .01m

100cm = 1m

*A small cube 1 cm on each side

Volume of Liquids

Use a graduated cylinder to measure volume

units = (ML) or CM3

1 ML = 1 CM3

Read from the bottom of the meniscus

Box Questions - page 8

3. 50CM3 of water are required to fill a graduated cylinder to the 50.0-mL mark.

4. A has a greater volume than rectangular box B but the length of box A is less than the length of Box B because A has bigger height or width.

5. the volume of the stone is 7CM3.

6(a). Eight (8) cubes will be needed to build a cube that measures 2 cm along each edge.

6(b). Twenty-seven (27) cubes will be needed to build a cube that measures 3 cm along each edge.

6(c). The volume of each of the cubes in (a) and (b) is 8+27 = 35CM3

7. The second box has the larger volume.

8. The divisions are not equally spaced because the cone shaped graduate used for measuring the volume of liquids is wider on top and than it becomes narrower.

## Lab Safety Notes

FOR EVERY LAB

*Goggles must be kept over your eyes (until Mr. Leeds says to put them away).

*Report accidents to Mr. Leeds immediately.

*Use common sense.

IN CASE OF EMERGENCY - Nurse ext: 2828

SAFETY EQUIPMENT IN CLASSROOM

Fire extinguisher

Fire blanket

Eye wash / shower

CHEMICALS

*Never taste.

*WAFT liquids to detect odor

*NEVER waft solids / powders

*Avoid touching chemicals

*Wash hands with soap / water after lab

*If chemicals touch skin - flush skin with water for 1 minute AND notify Mr. Leeds

GLASS

*Hot and cold glass look the same

*Never use chipped or broken glass

*Never use force to remove or insert glass

ALCOHOL BURNERS

*Roll up sleeves, put up long hair

*Never walk away from a lit burner

*Never point the open end of a hot test tube at yourself or someone else

*Don't look down into a test tube or beaker while it is being heated

*Make sure the burner is capped and the flame is out when done

END OF EXPERIMENT

*Clean up area and materials completely!!!

*Make sure the burner is out if one was used

*Keep goggles on (over eyes) until Mr. Leeds says to put them away

## 1st test

You must be able to find the water level of a cylinder and 3 cups flour is volume, 1 teaspoon is volume, pound of pumpkin is mass. Teaspoon of vanilla is volume, cinnamon is other means.

To find the sensitivity of the balance you find the change in mass over the number of yes's.

## Chapter 2 Test Part 1

Errors:

• Mass of gas= The cap not on tight enough
• Mass of copper and sulfur=The rubber sheet pops off.
• Ice and water lab= Condensation out side the bottle

## Part 2: Analysis

If you forget to put the cap on the bottle during the ice and water lab it creates artificial mass. Chapter 2 there should be no change in mass because of the law of conservation. During a lab a group dissolves 2 grams of salt into 8cm3 of water and left uncovered after a few days what will remain in the bottle? A: 2g of salt.

## Test 3.1-3.8

2. 2 necklaces contain 0.8 kg of platinum. If the density is 21.4 the volume is 37.4.

ALWAYS USE SCIENTIFIC NOTATION

Also remember David that it is MF-MI is the delta M or change in mass.

Epsom salt is the street name for MAGNESIUM SULFATE.