w5/w6 reagent preparation Flashcards
solution
mixture of substances has two parts a solute and a solvent
solute
substance that is dissolved so the NACL in a solution
solvent
substance that dissolves the water it would be distilled water
dilute solution
contain small portion of solute
concentrated solution
contain large portion of solute
diluent
agent that dilutes fluid
dilution
taking a measure of a concentrated solution and adding enough diluent to change the concentration to a lesser concentration
quantitative transfer what is it
preparing a reagent that is weighed and dissolved in a solvent to a specified concentration of volume you would
- calculations
- review WHIMIS AND SDS and make a workplace label
- accurately weigh solvent
- combine in a volumetric flask
- transfer to reagent for storage f
filtering solution
use medium retention filter if not specified. Whatman#1 fleet a diameter that will fit in funnel, fold paper in half twice and open into the funnel one layer thick on onside and three layers thick on the other side.
table one on page four look at and understand, can’t really be made into a flashcard
dont forget :P
rounding sig figs -if number to be dropped is five
you look at the number before 5 and you go to the nearest even number so 2.5 rounded to 2 and 1.5 is rounded to 2 as well
- number to be rounded increases by one if odd number
- number to be rounded stays the same if even number.
if number to be dropped is <5
less than five then the number to be rounded does not change 2.4 stays as 2
if number to be dropped is >5
greater than 5 the number to be rounded increases by 1
if the number to be dropped is 5 with digits after it
then the 5 is considered greater than 5 and the number will increase by one
2.15- round
2.2
2.25-round
2.2
6.6541-round
6.7
% weight per volume
%w/v=grams per 100ml of solution
used to express the concentration of solutions when a solid solute is mixed with a liquid solvent
-amount of solute placed in vessel and enough solvent added to desired volume- diluting to a final volume.
how would you perform calculation of % weight per volume
% weight is used as grams over 100ml and then that is = x amount of grams ( what you are looking for) over your desired volume then you would cross multiple to determine how many grams of solute you’d need
example of a % weight per volume question , how to solve
how would you prepare 500 ml of an 0.85% saline solution
you’d do 0.85/100= xgrams/500 then solve from there
what to do for mg% weight per volume
calculations are same as % weight per volume except you’d use mg over 100 ml and then you’d convert afterwards
what is % volume per volume
%v/v= mL per 100mL of solution
- expresses concentration and is used when a solution is a liquid solute in a liquid solvent.
- When making the desired volume of solute is placed in the graduated cylinder or flask then the solvent is added to the desired total volume - kind of like a dilution -same ratio as %w/v
how to calculate% v/v
the concentration that you want or desire is put over 100ml to make that percent of solution then the concentration of the total volume of the solution that you want, then you’d solve for the amount of liquid that you need to add to the amount of volume that you want to get the concentration that you want
ex: 200 ml of 60% alcohol
you would do 60/100=x/200
how would you prepare 250ml of 95% ethanol
95/100=x/250
you are assuming that the concentration of the ethanol that you are diluting is 100 percent and it wills specify if it is not and there is a different calculation for this
molar solutions
- mole is gram molecular weight of a substance
- one mole contains 6.022 x10 exponent 23 particles. and it is weight in grams
- molar mass is on periodic table – it is the elements number so you can find the molar mass of KNO3 by adding the values together.
molarity of a solution
ratio of number of moles of solute per litre of solution mol/l like concentration
a solution of 1 mole in 1L has a molarity of 1
ppm
parts per million -used for small concentrations
dilutions
making a weaker substance from a more concentrated one. they are written as a fraction. 1/4 1refers to liquid being diluted and the 4 refers to the total volume of the FINAL SOLUTION the difference so 3 would be the amount of diluent used
what dilution is made if 5ml of absolute ethanol added to 20ml of distilled water
solute volume/total volume
5ml/ 5ml+20 ml = 5 over 25 which is one fifth
-you have to add both amounts to determine the total volume
how would you make 1/2 dilution of serum
you’d pipette one 1ml of serum then add 1ml of water to make a total solution of 2ml
dilutions 1/x and preparing a volume
concentration is not changing but volume is changing
-so 1/5 dilution of bleach is what you want, how would you make say 250 ml of that you would do
1/5=x/250 ml you are solving for the amount of bleach needed to have a 1/5 dilution
how would you prepare 1L of 1/10 dilution of bleach
you would put 1/10=x/1000ml(convert) then solve so 100ml of bleach and 900 ml of water
how to determine concentration after a dilution
multiply the original concentration with the dilution so a 5% solution of HCL is dusted 2/5 so then just 5x2/5 is 2% it will always be less
how to determine concentration after multiple dilutions
multiply the original concentration by all the dilutions say 7% solution diluted 1/7 then 1/10 it would be a 0.1% solution
solution of 36% w/v solution has been diluted 1/8 what is the concentration of the diluted solution
38 x 1/8 is 4.5
when are patient specimens diluted
when analyze is too high to measure ( so this would mean that the instrument can’t pick it up) if 1/2 dilution is made to patients serum and the result was 16mmol this is technically incorrect, you need to correct the dilution.
how to correct dilution made on patient sample 1/2 dilution of patient serum, result is 17mmol/L
dilution concentration x dilution factor= original concentration
-the dilution factor would be the flipped fraction
17mmol/l x 2/1 = 34mmol/L and this value can be reported
how to change concentration
a stronger solution is diluted to make a specific amount of a weaker solution. the volume of one solution times the concentration of that solution equals the volume of the second solution times the concentration of the second solution-mumbojumbo
V(stronger)xC(stronger)=V(weaker)xC(weaker)
or V1C1=V2C2
INVERSE RELATIONSHIP
if the concentration is absolute you would use the v/v ratio to solve the problem.
how much 30% v/v alcohol is required to make 100ml of 3% alcohol, how to set up problem?
VsCs=VwCw
we dont know the volume of the stronger solution needed to make this
vs(30%)=(3%)(100) then you’d solve for the volume of the stronger solution
WHMIS 2015 info
federally and provincially legislated hazard info system started 1988. 2015 aligns with Globally Harmonized System classification and labelling of chemicals or GHS
3 components of whims
safety data sheets
labelling
worker eductation
what does WHMIS stand for
workplace hazardous material information system
two hazard groups
numbered 1-4 depending on severity
-physical hazards:physical and chemical properties -flammability, or reactivity. there are 19 classes in this group
-health hazards-classified based on adverse side effects to health, carcinogen, toxic
there are 12 classes in this group
physical hazards (19)
combustible dust* corrosive to metal flammable aerosol flammable gases flammable liquid flammable solid gases under pressure organic peroxides oxidizing gases oxidizing liquids oxidizing solids pyrophoric gas pyrophoric liquid pyrophoric solid self-heating substances and mixtures self-reactive substances and mixtures simple asphyxiants substances that when mixed with water emit flammable gases physical hazards-other
health hazards
acute toxicity aspiration hazard biohazardous infectious materials carcinogenicity germ cell mutagenicity reproductive toxicity respiratory or skin senstiization skin corrosion or irritation specific target organ toxicity -repeated exposure specific target organ toxicity- single exposure health hazards not otherwise classified
what is a SDS
safety data sheet
detailed info on safe handling and precautions taken when using hazardous products - written by manufacturer of product and must be updated every 3 years
SDS identification section
product name and and alternate names
product uses
supplier contact info
SDS hazard information
hazard identification
label requirements : pictogram signal word hazard statements and precaution statements
SDS composition and information on ingredients
hazardous substances : chemical name, common name and chemical abstract service number
each hazardous ingredient
SDS frist aid measures
first aid measures by route of exposure and most important symptoms
SDS fire fighting measures
suitable and unsuitable extinguishing media
specific hazards
special PPE
SDS accidental release measures
PPE, emergency procedures, personal precautions
methods and material for containment and cleanup
SDS handling and storage
- safe handling
- safe storage conditions including incompatible materials
SDS exposure controls and ppe
ppe
exposure limits
SDS physical and chemical properties
appearance odor pH melting freezing point boiling point flash point flammability explosive limits
SDS Stability and reactivity
conditions to avoid and incompatible materials
SDS toxicological info
description of various toxic health effects for routes of exposure and symptoms delayed and acute effects from short and long term exposure
SDS ecological info
optional to include
ecotoxicity persistence degradability bioaccumulation mobility in soil
SDS disposal considerations
optional safe handling and disposal methods
SDS transportation
stuff for that
SDS regulatory info
product safety and envronmental regulations
what is required by law
suppliers of products that fall under WHMIS legislation are required by law to provide SDS with product
who’s responsibility is it to make SDS available
employer
who’s responsibility is it to know where SDS located
employee
what are on supplier labels (6)
- product identifier-brand name-chemical name
- hazard pictograms-visual display of symbol
- signal words- danger or warning to catch attention
- hazard statement- describe type of hazard
- precautionary statements- standard precautions to minimize and prevent exposure PPE storage handling
- supplier identifie
workplace labels are used when
a hazardous substance is transferred from an original container to another container
the supplier label is destroyed or missing
hazard materials were produced on site
when is a workplace label not required
the product is transferred to a container for immediate use
the product is in the control of the individual who aliquoted it
information to include on workplace label
name of product matching the SDS name safe handling instructions pictogram SDS available PPE when it was prepared and by who concentration
pictogram gas cylinder
gasses under pressure
pictogram flame
- flammable gases aerosols liquids or solids
- pyrophoric
- self heating
- contact with water makes flame
- organic peroxides
- self reacting
pictogram flame over circle
oxidizing gases liquids and solids
pictogram exploding bomb
self reactive
organic peroxides
pictogram stuff pouring on hand and metal
corrosion
corrosive to metal
corrosive to skin
serious eye damage or irritation
pictogram skull and crossbones
acute toxicity-derma oral or inhalation
pictogram black person with white star in chest
health hazard -respiratory or skin -germ cell mutagenicity carcinogen -reproductive toxicity -specific organ toxicity to repeated or one time exposure aspiration hazard
pictogram exclamation mark
- acute toxicity-dermal inhalation or oral
- skin corrosion
- eye damage serious
- respiratiory skin sensitization
- specIfic raget organ toxicity SINGLE EXPOSURE
pictogram 3 circles overlapping
biohazardous infectious materials
pictogram dead tree and dead fish on the shore near the dead tree which may or may not be in water
environmental hazard
hazardous to aquatic environment
what is the most important part of whmis
EDUCATION
-employer has responsibility to educate workers
education must include- instruction , trainman , provision information
what is the worker or employee responsible for in regard to education
- receiving and learning info
- informing the employer if information is lacking or wrong
- working with the employer to implement program for safe handling of controlled products- so following the rules
compressed gas -transport and hooking it up to gas cylinder
-leak or bent=pressure can cause gas to fly around
transport-move regulator put protection cap on-use trolley- do not allow tanks to hit each other
hooking up to gas cylinder-strap securely-be sure regulator is correct one for use- connections tight-never oil or grease valves, gauges or regulators
flammable range of a chemical
- range of vapour concentration per amount of air in which the mixture will burn -vapour concentration per oxygen concentration
- to lean-not enough material to cause fire
- to rich - to much and not enough oxygen to ignite
flash back cause
vapours accumulate on floor or bench and travel far and wide, when they ignite at open flame the flame goes all the way back
flash point
lowest temp at which liquid gives off vapour in sufficient quantity to form a flammable mixture with air- low flashpoint is more dangerous ether -45 acetone -20 toluene -4 alcohol 12 xylol 25
how to prevent vapours
work in fume hood
do not have flames or sparks nearby when working
metal containers should be bonded and grounded when pouring one to another in order not to produce sparks
fires -what are they extinguished with
CO2 or ABC fire extinguisher, dont use water the solvent will float on water and just move the fire
storage of flammable chemicals
- store minimum quantities
- large amount stored in cool, well ventilated fire proof room
- never store near oxidizing materials
- watch expiration date of ether- it forms shock-sensitive explosive peroxides when old or exposed air is to sunlight, dispose of after 3 months of opening
disposal of organic chemicals
cannot be discarded into city sewer system- chemical collected in appropriate container labelled and sent to disposal plant
what to do if flammable material spilt
use spill clean-up kit first shut off all sources of ignition procedure -don gloves supplied -sprinkle charcoal to dike then a lot to absorb -use scoop to mix charcoal and solvent until it is dry with no odor -scoop into bag -place scoops and gloves into bag -seasl bag -fill out disposal label and put on bag -dispose bag with lab regulations
what are corrosive materials
cause damage to metal or body tissue HCL hydrochloric sulfuric acid -H2SO4 NaOH sodium hydroxide KOH potassium hydroxide
precautions when working with corrosive chemicals
wear rubber gloves and apron and face shield
ADD CORROSIVES TO WATER
ad slowly while swirling flask - allow it to cool if it getting too hot
pour with container below eye level and label side up to prevent drips
flush chemical burns with water for 15 minutes
transport corrosives in safety carriers
storage of corrosive chemicals
store acids separate from bases
store minimal amounts
corrosive spill
acid spill kid -neutralizer -sodium bicarbonate and pH indicator
-caustic spill kit(basic) - alkali neutralizer citric acid and pH indicator
solvent spill kit-charcoal neutralizer
universal- absorbant pads/ pillow- kitty litter, sodium bicarbonate and sand most acid base and solvent spills
corrosive clean up procedure
- don
- sprinkle absorbant material out to in-colour change
- foaming subside mix with scoop until pH neutral
- put everything in bag tie and label bag for disposal
what can you pour down drain of acids
dilute solutions with water running
neutralize concentrated solutions then run water
larger amount sent to plant
how do toxic substances enter body
inhalation vapours aerosols
ingest
absorb from skin
LD50
lethal dose 50
quantity of a substance that when administer by route of entry expected to cause death of 50% of defined animal population mg or g per kg of animal body weight
LC 50
lethal concentration - concentration of substance that in air inhaled over a specified amount of time is expected to cause death 50% of the time in a defined animal pop expressed in part per million or mg/M3
TLV
threshold limit value -max limit of exposure to air
PEL
permissible exposure limit-max limit of exposure to air
8hour TWA
time-weighted average
average concentration over an 8 house period representing conditions under which it is believed that all workers my be repeatedly be exposed day after day without adverse health effects
STEL
short term exposure limit-max concentration to which workers can be periodically exposed for 15 minute intervals without adverse health effects
Ceiling limit
concentration of airborne substance which must need be exceeded and is applied to many chemicals with acute toxic effects
common toxic chemicals
acetone
formaldehyde
methanol
xylene
how are hydrocyanic acid vapours formed?
mixing cyanide with acid
mercury
insidious hazard progresses imperceptibly but harmful -only in thermometers -liquid mercury releases vapour at a rate to exceed permissible exposure levels -has own spill kit
precautions to working with toxic chemicals
work in fume hood
where ppe
wash contacted area for 15 minutes
