Chem 123L Exam I

If you spill a chemical on yourself, what two things should you do?

- remove all clothes
- sit under the shower for 15 mins

If you spill a chemical on your eyes, what two things should you do?

- holy eyes open
- rinse for 15 mins

When using a fire extinguisher, what does the acronym PASS mean?

P - Pull
A - Aim
S - Squeeze
S - Sweep

If you get a large cut and is exposed to chemicals, what two things should you do?

- Tell the professor/instructor
- Consult the SDS book

Flammable Chemicals Sign

Oxidizers Sign

Corrosive Chemicals Sign

What is the scale for the safety diamond? What does it mean?

0 to 4, 0 being the least dangerous while four being the most dangerous

What does the safety diamond's red section talk about?

Flammability

What does the safety diamond's blue section talk about?

Health Hazards

What does the safety diamond's white section talk about?

Special/Specific Hazards

What does the safety diamond's yellow section talk about?

Reactivity Hazard

In a lab, your shoes must be ____________________.

closed

In a lab, you must wear _______________ over your legs

pants

In a lab, there is no ________________ allowed on ears, face, or wrists

jewelry

In a lab, long hair must be __________________.

tied back

In a lab, _____________ must be on at all times to protect your eyes

goggles

When removing gloves, what must you not touch?

The outside of the glove with your bare hands

What resource properly tell us how to dispose of chemicals

the SDS book

Aqueous Waste is disposed in a ______________________
Glass Waste is disposed in the _________________
Needles are disposed in the ________________________
Solids are not disposed in the ____________________

- bottled glass
- glass box
- sharps box
- trash

If mercury is spilled, use _____________ to clean it up

Sulfur

Chemicals should ideally be stored in where

cool, dry, dark cabinets

Never mix ___________________ when collecting solid chemicals and never return ______________ if too much is collected

spatulas / chemicals

Mega - _________________ (M)
Kilo - _________________ (k)
deci - _________________ (d)
centi - _________________ (c)
mili - _________________ (m)
macro - _________________ (µ)
nano - _________________ (n)

M - 10^6
k - 10^3
d - 10^-1
c - 10^-2
m - 10^-3
µ - 10^-6
n - 10^-9

Beaker

Erlenmeryer Flask

Funnel

Graduated Cylinder

Pippette

Burette (and three parts)

barrel, stop cock, tip

How many significant figures for:
Burette _____________
Pipette _____________
Graduated Cylinder _____________
Erlenmeyer flask _____________
Scale _____________
Beaker _____________
Thermometer _____________

Burette 4

Pipette 4 (or 2)

Graduated Cylinder 3

Erlenmeyer flask 3

Scale all of the digits present

Beaker 3

Thermometer 3

Formula for Percent Error

| Theoretical - Experimental | x 100

Theoretical

In a solution, the _______________ is totally dissolved by the ________________

solute is totally dissolved by the solvent

a homogeneous mixture of two components: the solute and solvent

solution

The minor component in a solution is the _______________ and is totally used up in the reaction

solute

The bigger component in a solution is the _______________ and is leftover after a reaction takes place

solvent

Once the molarity of a solution is known it can be called a _______________________

Standard Solution

How close each trial is to one another

percision

How close each trial is to the target goal

accuracy

A data point that is outside the accepted range of data

outlier

For data to be precise, they should be within ___________ of one other

0.005

Is used to determine the concentration of a solution by comparing it with a set of solutions of known concentration

calibration curve

How do you calculate density

mass divided by volume

How do you prepare a standard solution

The mass of solute needed is calculated and weighed. (b) The solute is dissolved in some distilled water in a beaker. (c) The solution is transferred into a volumetric flask.

When the concentration of a solution needs to be exactly known use the technique known as ________________

titration

the process of slowly adding one reactant to another, and measuring how much is needed for the subsequent reaction to be complete

titration

The reactant which is added slowly from a buret

titrant

the reactant being neutralized during the titration is called the _____________, usually the acid

analyte

occurs when the analyte completely reacts with the titrant and no additional titrant is present in the titration solution

equivalence point

Aliquot

exact portion of a solution

When the indicator changes color and the titration is complete

end point

The indicator used in the experiment is ______________________

phenolphthalein

A compound that changes color in the presence of an acid or a base

indicator

How do you calculate molarity

moles of solute/liters of solution (mol/L)

What happened in the Introduction to Chemistry Lab

The same volume of water was delivered using different times of measuring devices. With each glassware we tried to determine the actual volume of water delivered by measuring its mass. (We used the formula D=m/V, using the table of densities and the mass we found to see the actual amount of volume delivered)

Goal of Introduction to Chemistry Lab

Find the volume of water actually delivered using the formula D=m/V

What happened in the Density of Salt Solutions Lab

- We first made a 5% concentrated solution by diluting a 10% solution of NaCl.
- Then with the 5% and 10% solutions, we measured and found the mass of the solution a specific volume. We then did this same thing we an unknown solution.
- Then we used the densities (found by the mass and volumes) to graph them against their percentages and found a calibration curve.
- With the calibration curve and the density of the unknown solution, we were able to find the percentage of concentration of the unknown solution

Goal of the Density of Salt Solutions Lab

Find the concentration of the unknown solution by using a calibration curve

What happened in the Acid Base Titration Lab

- A buret was prepared and filled with NaOH
- A solute was then prepared with an indicator
- Then slowly the NaOH was added to the solute until it became a bright pink
- Once the volume of NaOH added was known, you then calculated the amount of mols used (with the known molarity
- Once you knew how many moles of NaOH was used, you could find how many moles of solute was used
- Then using the number of solute moles, you could calculate the molarity of the solute.

Goal of the Acid Base Titration Lab

Find the molarity of the solution being titrated