GEN CHEM 1 | ETA REVIEWER

Ring Stand

It supports the Bunsen burner, iron ring, pipestem triangle, and other items, often while heating a substance.

Pipestem Triangle

supports the crucible when being heated over an open flame.

Evaporating Dish

used to evaporate excess solvents to create a more concentrated solution.

Test Tubes

used to hold small amounts of liquids for mixing or heating

Beaker

used to hold water and to heat other chemicals, especially, liquids

Erlenmeyer flask

a narrow-mouthed container used to
transport, heat, or store substance; often
used when a stopper is required

Volumetric Flask

calibrated to contain a precise volume at a particular temperature; used for precise dilutions and creating standard solutions

Watch Glass

used in keeping liquid contents in a beaker from splattering

Mortar & Pestle

used to grind chemicals into powder

Iron Ring

supports a beaker over a Bunsen burner; wire gauze is usually placed on top of this structure

Utility Clamp

used to hold a test tube or other piece of equipment in place on a ring stand

Wire Gauze

used for suspending glassware over the Bunsen burner

Tongs

used to transport a hot beaker, as well as remove the lid from a crucible

Triple-beam balance

used in obtaining the mass of an object

Test Tube Clamp

used to hold a test tube when heating its contents

Bunsen Burner

used for heating (flame-safe) contents in the lab

Foreceps

used in dissection to grasp tissues or pick up small items

File

used to grind down materials or sharpen items

Wire Brush

used to clean the inside of test tubes or graduated cylinders

Test Tube Rack

used in holding multiple test tubes filled with chemicals; or for drying after washing

Funnel

used to pour liquids into containers with small openings; also used to hold filter paper in a filtration setup

Scoopula

used in scooping solids/powders

Graduated Cylinder

used for measuring specific amounts of liquids, and has different measured graduation

Spatula

used in measuring/removing small amounts of solids or powders (often when obtaining mass)

Wash bottle

used to wash down specific pieces of equipment with water or keep materials moist

Micropipets

used to measure and dispense very small amounts of liquids (ex. 0.5 mL)

Buret

used in measuring specific amounts of liquids; and often in determining amounts of acids or bases needed (ex. 13 mL). It is also used in releasing small amounts of acids or bases into other solutions

Dropper

used to obtain small amounts of liquids, but is not precise

Thermometer

used to measure temperature

Pipet

used to measure and dispense small amounts of liquids (ex. 1 mL)

Well plate

used in mixing very small amounts of chemicals together and comparing results

Corks

used to seal or stop flasks or test tubes

Hot Plate

used for consistent heat; used to heat substances that may be flammable

Florence Flask

has a round body and flat bottom. It is used to hold and heat liquids

Reagent Bottles

dark colored bottles that protect chemicals from light; chemicals are obtained using a spatula

Transferring Solid Chemicals into Test Tubes

1. Fold a clean rectangular piece of paper lengthwise.

2. Put the solid reagents at the edge of the paper.

3. Hold the test tube in a horizontal position and slide the paper in until it touches the bottom of the test tube.

4. Incline the tube and gently tap the paper to ensure that the reagent reaches the bottom and not the sides.

Electronic Balances

allows one to quickly measure the mass of a substance with a high level of accuracy.

Tare/Zero Button

After placing a container on the scale, pressing this resets the scale to zero. This lets you place the reagents into the container and provides you an accurate measurement, since the mass of the container is no longer accounted for.

Ways to Transfer Liquid Reagents

1. Make the neck of the container the reagent is in must touch the receiving vessel.

2. Lean the neck on to a stirring rod, especially in narrow mouth containers.

3. Use a medicine dropper or pipette to transfer small amounts of liquids.

Measuring Liquid Substances

Pour the liquid into a graduated cylinder until the liquid meniscus is at the desired measurement. Base the volume’s value on the line aligned with the liquid meniscus, and add an additional significant figure at the end of the known measurement.

Liquid Meniscus

the lowest point of a curved surface when measuring its volume in a graduated cylinder

Measuring the Volume of an Irregular Object

1. Pour some liquid into a graduated cylinder and record the initial volume.

2. Place the object inside and record the new volume. It should be higher than the initial due to water displacement.

3. Get the difference between the two values.

Gas Valve

contains and controls the amount of gas relayed to the burner

Hose

is how the gas travels from the gas valve to the needle valve

Needle Valve

controls the quantity of gas admitted to the burner

Air intake openings

how air needed for combustion enters burner

Collar

small disk at the bottom that is turned to control the amount of air entering the barrel

Base

support for the burner

Barrel

raises the flame to a suitable height for heating; it is where gas and air mix for combustion

Inner Blue Cone

The most visible part of the flame, which contains the hottest region at the tip

Outer Nonluminous Flame

the lighter part of the flame

Safety Flame

It is color yellow/orange. It is the coolest at 300 degrees, and it merely indicates that the burner is on.

Blue Flame

Also known as an invisible flame, it is difficult to see and is the kind of flame that is usually used. It is around 500 degrees.

Roaring Blue Flame

It is the hottest flame at 700 degrees and makes noise. It has a blue triangle at the center

Using the bunsen burner

• Light the burner and turn on the gas control at the same time.

• Slowly open the air hows.

• Use the collar to adjust the flame’s color and height.

• To close the bunsen burner, turn off the air holes followed by the gas control.

Heating Set-Up

A bunsen burner is placed at the bottom of a ring stand. The ring is fastened to the pole of the ring stand. The iron clamp should not be too fastened to prevent the expanding glassware from breaking.

Heating a Beaker

A wire gauze is placed on the ring. Then, the beaker with the reagent is placed on top of the wire gauze.

Heating with a Crucible

Place a clay triangle on the iron ring. Then, place a crucible containing the reagent on top of the clay ring and cover it.

Heating a Test Tube

Hold the test tube with a test tube holder at an angle of 45 degrees over the flame. Heat the reagent by slowing passing the bottom part back and forth over the flame.

Preparing Fluted Filter Paper

1. Fold the circular paper in half three times in the same direction until you have a 1/8 section cone.

2. Unfold the paper twice to get a semicircle.

3. Alternately fold up and down every eighth of the semicircle to create a fan-fold.

4. Open the fan until you get a fluted filter cone, similar to a shell.

5. Find the two opposing ends that are not folded properly and fold them inward.

Titration

A solution with a known concentration called the titrant is dispensed by a burette and reacts with a solution with an unknown concentration called the analyte. It helps you know how much of the titrant is needed to neutralize a solution, usually used in acid-base reactions.

End Point of a Titrant

Indicates when titration is complete through the change of color of an indicator solution

Equivalence Point of a Titrant

when the number of moles of the titrant and analyte are equal

Steps in Titration

1. Rinse the inside of the burette with the titrant at least twice.

2. Once dry mount it to the ring stand with the burette clamp.

3. Place a beaker with the analyte under the solution. Add some of the indicator solution

4. Fill the burette to above the zero mark.

5. Run some solution through the stopcock to fill the burette tip completely.

6. Record the starting volume.

7. When titration is over, record the final volume.

8. Get the difference between the two volumes to know how much solution was added.

Distillation

It is used to separate the components of a liquid mixture. By separating them based on boiling points.

Boiling Flask

This is where the mixture is heated.

Liebig condenser

The vapor of one of the liquid components is cooled back into liquid using the cooling water.

Receiving Flask

This is where the liquid with the lower boiling point goes.

Distillation Column

It is used to separate the two substances through heating and cooling.

Steps in Distillation

1. Attach the boiling flask with the mixture onto the clamp stand using the clamp. Place the bunsen burner under it, and place the thermometer in the flask to monitor the temperature.

2. Attach the distillation column to the boiling flask and the condenser to the distillation column. Place the receiving flask at the other end of the condenser.

3. Heat the boiling flask. Use the thermometer to slowly adjust the heat if needed.

4. Collect the distillate as it drips into the receiving flask.

Physical Change

change in physical properties and not its chemical identity nor composition, does not lead to the formation of new susbances

Intensive Properties

inherent physical properties, does not depend on amount of substance (color, temperature, density, solubility)

Extensive Properties

depends on the amount of substance (size, volume, weight)

Melting

solid to liquid

Freezing

liquid to solid

Evaporation

liquid to gas

Condensation

gas to liquid

Deposition

gas to solid

Sublimation

solid to gas

Chemical Change

change in chemical composition through rearrangement of atoms into a new substances with significantly different properties; substances reacts and produces a new substances

Evidences/Indicators of Chemical Change

• evolution of gas - bubbles in reaction

• evolution of heat - release of absorption of heat

• color change

• odor production

• formation of precipitate - insoluble solids formed

Reactants

substances that are used in the reactions, written on the left side of reaction

Products

substances that formed from the reaction, written on right side of reactions

Phases

indicated by (s) for solid, (l) for liquid, (aq) for aqueous solution, or (g) for gas on the right of the involves substances to indicate their phases

Plus Sign

indicate combination of substance

Arrow

to form or to yield

Coefficients

the big number that indicates the number of molecules of the substances; always a whole number

Subscripts

the smaller number that indicates the number of atoms of a certain element; always a number

Diatomic Molecules

elements that naturally appear in nature as a gas with two combined atoms

Diatomic Elements

Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, Bromine

Combination Reaction | Definition

also known as synthesis reaction, multiple reactants combine to form a single product

Combination reaction | Formula

X + Y → XY

Decomposition Reaction | Definition

As the opposite of the combination reaction, a single compound breaks into two or more simpler substances

Decomposition Reaction | Formula

XY → X + Y

Single Displacement Reaction | Definition

also known as a substitution reaction, a more reactive element displaces a less reactive element from its aqueous salt solution

Single Displacement Reaction | Formula

X + YZ → XZ + Y

Double Displacement Reaction | Definition

also known as a metathesis reaction, ions get exchanged between two reactants which a new compound

Double Displacement Reaction | Formula

XY + ZA → XZ + YA

Monatomic Ions

Ions based on elements in groups 1A, 2A, 3A, 5A, 6A, 7A

Cations

Ions found in groups 1A, 2A, and 3A