Salt content of snack foods
Group number:U11
Title of investigation
Salt content of snack foods Aims
To determination determination the salt content in potato chips by b y using Mohr method and Volhard method. Reason for carrying out the investigation
The nutrition labels are different from the experimental reports of The entre of !ood Safety. "umber of experiments to be conducted: # Titles of the experiments
A. Mo Mohr hr Met Metho hod d $n this method% the amount of chloride ions are determined by titrating the sample &ith a standard solution s olution of 'g()a*+% using r,-#)a*+ as an indicator. 'g( )a*+ ions react &ith both l )a*+ and r,-# )a*+ ions to gi/e precipitates. 0o&e/er% since 'gl)s+ has a lo&er solubility than 'g#r,-)s+% 'gl)s+ is formed first. 'fter all l)a*+ ions in the sample are consumed% the first drop of 'g ( )a*+ in excess &ill react &ith the chromate indicator% gi/ing a red precipitate. 'g( )a*+ ( l )a*+
→
'gl)s+
# 'g 'g( )a*+ ( r,-# )a*+
recipitation 2eaction
'g 'g#r,-)s+
3ndoint 2eaction
→
$n this method% neutral medium should be used since% in alkaline solutions% sil/er ions &ill react &ith the hydroxide ions and form 'g #,)s+. $n acidic solutions% sil/er chromate)V$+ &ill be dissol/ed. Therefore% the p0 of solution should be kept at about 4. $f an acidic solution of a chloride is to be analysed% the follo&ing alternati/es can be considered: "eutralise the acid &ith excess calcium carbonate )chloride free+ and use potassium chromate as indicator in the titration5 'dd excess sil/er nitrate and estimate the excess by potassium thiocyanate )see Volhard Method belo&+ 5 Use an adsorption indicator )!a6ans7 Method+. Method+.
1
Salt content of snack foods
Group number:U11
B. Volhard Method $n the Volhard method for the determination of chloride and other anions% a measured /olume of standard sil/er nitrate solution is added to the sample solution5 excess amount of sil/er nitrate is needed to react &ith the halide: 'g()a*+ ( 8)a*+
'g8)s+ ( excess 'g()a*+
→
recipitation 2eaction
The excess sil/er ion is then backtitrated &ith standard thiocyanate using saturated ammonium iron)$$$+ sulphate solution as indicator: S")a*+ ( excess 'g()a*+ S")a*+ ( !e()a*+
→
'gS")s+
!e)S"+#()a*+
9ackTitration 2eaction 3nd oint 2eaction
→
$f the sil/er halide precipitate is less soluble than sil/er thiocyanate% the excess sil/er ions can be titrated directly &ith potassium thiocyanate. This applies to sil/er bromide and sil/er iodide.$n the titration% the acid medium is necessary to pre/ent the precipitation of !e( ions as their hydrated oxides. 0o&e/er% sil/er chloride is more soluble than sil/er thiocyanate and must be remo/ed by filtration so that it is not con/erted to sil/er thiocyanate during the titration: S")a*+ ( 'gl)s+
'gS")s+ ( l )a*+
→
Materials Required
1.
Standard ;.1 M sil/er nitrate solution
#.
otassium chromate )V$+ indicator solution )< =% about ;.#< M+
.
otassium thiocyanate solution );.;< M+
-.
'mmonium iron)$$$+ sulphate solution )saturated+
<.
"itric acid )1:1% concentrated% >M and /ery dilute+
Safety
1.
"o eating or drinking is allo&ed in the laboratory.
#.
"e/er ingest any snacks used in the experiments.
.
?o not touch any hot ob6ects &ith your bare hands.
-.
'/oid direct contact &ith chemicals.
<.
@ash immediately &ith plenty of tap &ater if chemicals spill on your skin.
>.
Aeep sil/er nitrate a&ay from your skin and clothes. Sil/er salts are readily reduced tometallic sil/er &hich forms stains that are difficult to remo/e. #
Salt content of snack foods
4.
Group number:U11
@ear suitable glo/es and eye protection. Use a fume cupboard if the solid is a fine po&der.
Risk Assessment Hazards Identifcation o Potassium chromate(VI) Emergency !er!ie" #A$%E&' &$% *I#I+E&. ,$A, -IH HE& MAE&IA MA/ ,A0E A 1I&E. ,&&IVE. ,A0E EVE&E B0&$ EVE&/ A&EA 1 ,$A,.
HA&M10
I1
-A-E#
&
I$HAE#.
A11E,
HE
&EPI&A&/ /EM2 IVE&2 3I#$E/2 E/E2 3I$ A$# B#. MA/ ,A0E AE&%I, &EA,I$. ,A$,E& HA+A&#. ,A$ ,A0E ,A$,E&. &is4 o cancer de5ends on duration and le!el o e65osure.
o6icological Inormation ral rat #789 :;8 mg<4g. In!estigated as a tumorigen2 mutagen2 re5roducti!e e=ector.
Potential Health E=ects Inhalation9 ,orrosi!e. E6tremely destructi!e to tissues o the mucous mem>ranes and u55er res5iratory tract. May cause ulceration and 5eroration o the nasal se5tum. ym5toms may include sore throat2 coughing2 shortness o >reath2 and la>ored >reathing. May 5roduce 5ulmonary sensitization or allergic asthma. Higher e65osures may cause 5ulmonary edema. Ingestion9 ,orrosi!e. "allo"ing can cause se!ere >urns o the mouth2 throat2 and stomach2 leading to death. ,an cause sore throat2 !omiting2 diarrhea. May cause !iolent gastroenteritis2 5eri5heral !ascular colla5se2 dizziness2 intense thirst2 muscle cram5s2 shoc42 coma2 a>normal >leeding2 e!er2 li!er damage and acute renal ailure. 4in ,ontact9 ,orrosi!e. ym5toms o redness2 5ain2 and se!ere >urn can occur. #usts and strong solutions may cause se!ere irritation. ,ontact "ith >ro4en s4in may cause ulcers (chrome sores) and a>sor5tion2 "hich may cause systemic 5oisoning2 a=ecting 4idney and li!er unctions. May cause s4in sensitization. Eye ,ontact9 ,orrosi!e. ,ontact can cause >lurred !ision2 redness2 5ain and se!ere
Salt content of snack foods
Group number:U11
tissue >urns. May cause corneal in?ury or >lindness. ,hronic E65osure9 &e5eated or 5rolonged e65osure can cause ulceration and 5eroration o the nasal se5tum2 res5iratory irritation2 li!er and 4idney damage and ulceration o the s4in. 0lcerations at frst may >e 5ainless2 >ut may 5enetrate to the >one 5roducing @chrome holes.@ 3no"n to >e a human carcinogen. Aggra!ation o Pree6isting ,onditions9 Persons "ith 5ree6isting s4in disorders2 asthma2 allergies or 4no"n sensitization to chromic acid or chromates may >e more susce5ti>le to the e=ects o this material.
Handling and torage 3ee5 in a tightly closed container. Protect rom 5hysical damage. tore in a cool2 dry2 !entilated area a"ay rom sources o heat2 moisture and incom5ati>ilities. #o not store on "ooden oors. -ear s5ecial 5rotecti!e eCui5ment (ec. ;) or maintenance >rea4in or "here e65osures may e6ceed esta>lished e65osure le!els. -ash hands2 ace2 orearms and nec4 "hen e6iting restricted areas. ho"er2 dis5ose o outer clothing2 change to clean garments at the end o the day. A!oid cross contamination o street clothes. -ash hands >eore eating and do not eat2 drin42 or smo4e in "or45lace. ,ontainers o this material may >e hazardous "hen em5ty since they retain 5roduct residues (dust2 solids)D o>ser!e all "arnings and 5recautions listed or the 5roduct.
1irst Aid Measures Inhalation9 &emo!e to resh air. I not >reathing2 gi!e artifcial res5iration. I >reathing is dicult2 gi!e o6ygen. %et medical attention immediately. Ingestion9 I s"allo"ed2 # $ I$#0,E VMII$%. %i!e large Cuantities o "ater. $e!er gi!e anything >y mouth to an unconscious 5erson. %et medical attention immediately. 4in ,ontact9 Immediately ush s4in "ith 5lenty o "ater or at least :7 minutes "hile remo!ing contaminated clothing and shoes. %et medical attention immediately. -ash clothing >eore reuse. horoughly clean shoes >eore reuse. -
Salt content of snack foods
Group number:U11
Eye ,ontact9 Immediately ush eyes "ith 5lenty o "ater or at least :7 minutes2 liting lo"er and u55er eyelids occasionally. %et medical attention immediately.
Hazards Identifcation o 1erric Ammonium ulate Emergency !er!ie" ,aution' May cause irritation to s4in2 eyes2 and res5iratory tract.
o6icological Inormation $o
#78<,78
inormation
ound
relating
to
normal
routes
o
occu5ational e65osure. In!estigated as a mutagen.
Potential Health E=ects Inhalation9 May cause irritation to the res5iratory tract. ym5toms may include coughing2 sore throat2 la>ored >reathing2 and chest 5ain. Ingestion9 arge oral doses may cause irritation to the gastrointestinal tract. o" to6icity in small Cuantities >ut larger dosages may cause nausea2 !omiting2 diarrhea2 and >lac4 stool. Pin4 urine discoloration is a strong indicator o iron 5oisoning. i!er damage2 coma2 and death rom iron 5oisoning has >een recorded. 4in ,ontact9 May cause irritation "ith redness and 5ain. Eye ,ontact9 May cause irritation2 redness and 5ain. ,rystals may >e a>rasi!e. ,hronic E65osure9 $o inormation ound. Aggra!ation o Pree6isting ,onditions9 Persons "ith 5ree6isting s4in disorders or eye 5ro>lems2 or im5aired li!er2 4idney or res5iratory unction may >e more susce5ti>le to the e=ects o the su>stance.
Handling and torage 3ee5 in a tightly closed container2 stored in a cool2 dry2 !entilated area. Protect against 5hysical damage. ,ontainers o this material may >e hazardous "hen em5ty since they retain 5roduct residues (dust2 solids)D <
Salt content of snack foods
Group number:U11
o>ser!e all "arnings and 5recautions listed or the 5roduct.
1irst Aid Measures Inhalation9 &emo!e to resh air. %et medical attention or any >reathing diculty. Ingestion9 %i!e se!eral glasses o "ater to drin4 to dilute. I large amounts "ere s"allo"ed2 get medical ad!ice. 4in ,ontact9 Immediately ush s4in "ith 5lenty o "ater or at least :7 minutes. &emo!e contaminated clothing and shoes. -ash clothing >eore reuse. horoughly clean shoes >eore reuse. %et medical attention i irritation de!elo5s. Eye ,ontact9 Immediately ush eyes "ith 5lenty o "ater or at least :7 minutes2 liting u55er and lo"er eyelids occasionally. %et medical attention i irritation 5ersists.
Hazards Identifcation o Potassium hiocyanate Emergency !er!ie" -arning' Harmul i s"allo"ed or inhaled. ,auses irritation to s4in2 eyes and res5iratory tract.
o6icological Inormation ral rat #789 ;7F mg<4g. In!estigated as a mutagen2 re5roducti!e e=ector.
Potential Health E=ects Inhalation9 ,auses irritation to the res5iratory tract. ym5toms may include coughing2 shortness o >reath. Ingestion9 May cause 5sychosis2 !omiting2 disorientation2 "ea4ness2 lo" >lood 5ressure2 con!ulsions and death "hich may >e delayed. he 5ro>a>le lethal dose is >et"een :7G8 grams. 4in ,ontact9 ,auses irritation to s4in. ym5toms include redness2 itching2 and 5ain. Eye ,ontact9 >
Salt content of snack foods
Group number:U11
,auses irritation2 redness2 and 5ain. ,hronic E65osure9 Prolonged or re5eated s4in e65osure may cause dermatitis. &e5eated ingestion o small amounts may cause "ea4ness2 conusion2 central ner!ous system e=ects2 nausea and s4in eru5tions. Aggra!ation o Pree6isting ,onditions9 $o inormation ound.
Handling and torage 3ee5 in a tightly closed container2 stored in a cool2 dry2 !entilated area. Protect against 5hysical damage. Isolate rom o6idizing materials. tore in the dar4. ,ontainers o this material may >e hazardous "hen em5ty since they retain 5roduct residues (dust2 solids)D o>ser!e all "arnings and 5recautions listed or the 5roduct.
1irst Aid Measures Inhalation9 &emo!e to resh air. I not >reathing2 gi!e artifcial res5iration. I >reathing is dicult2 gi!e o6ygen. %et medical attention. Ingestion9 Induce !omiting immediately as directed >y medical 5ersonnel. $e!er gi!e anything
>y mouth
to an unconscious 5erson.
%et
medical
attention. 4in ,ontact9 -i5e o= e6cess material rom s4in then immediately ush s4in "ith 5lenty o "ater or at least :7 minutes. &emo!e contaminated clothing and
shoes.
%et
medical
attention.
-ash
clothing
>eore
reuse.
horoughly clean shoes >eore reuse. Eye ,ontact9 Immediately ush eyes "ith 5lenty o "ater or at least :7 minutes2 liting lo"er and u55er eyelids occasionally. %et medical attention immediately.
Hazards Identifcation o il!er $itrate Emergency !er!ie" Poison' #anger' ,orrosi!e. ,auses >urns to any area o contact. May >e atal i s"allo"ed. Harmul i inhaled. trong o6idizer. ,ontact "ith other material may cause fre. 4
Salt content of snack foods
Group number:U11
o6icological Inormation ral rat #789 ::G mg<4g. Irritation data2 ra>>it2 std #raize9 eye9 : mg2 se!ere. In!estigated as a tumorigen2 mutagen and re5roducti!e e=ector.
Potential Health E=ects Inhalation9 E6tremely destructi!e to tissues o the mucous mem>ranes and u55er res5iratory tract. ym5toms may include >urning sensation2 coughing2 "heezing2
laryngitis2
shortness
o
>reath2
headache2 nausea
and
!omiting. May >e a>sor>ed into the >ody ollo"ing inhalation "ith sym5toms 5aralleling those rom ingestion e65osure. #ust de5osits in the lungs may resem>le a orm o 5neumoconiosis. Ingestion9 ,orrosi!e. "allo"ing can cause se!ere >urns o the mouth2 throat2 and stomach. ,an cause sore throat2 !omiting2 diarrhea. Poison. ym5toms include 5ain and >urning in the mouth2 >lac4ening o the s4in and mucous mem>ranes2 throat2 and a>domen2 sali!ation2 !omiting o >lac4 material2 diarrhea2 colla5se2 shoc42 coma and death. 4in ,ontact9 ,orrosi!e. ym5toms o redness2 5ain2 and se!ere >urn can occur. Eye ,ontact9 ,orrosi!e. ,an cause >lurred !ision2 redness2 5ain2 se!ere tissue >urns and eye damage. ,hronic E65osure9 &e5eated
a55lication
discoloration
o
the
or
ingestion
s4in2
causes
con?uncti!a2
and
a
5ermanent
mucous
>luish
mem>ranes.
&e5eated inhalation may cause lung disease. Aggra!ation o Pree6isting ,onditions9 Persons "ith 5ree6isting s4in disorders or eye 5ro>lems or im5aired res5iratory unction may >e more susce5ti>le to the e=ects o the su>stance.
Handling and torage 3ee5 in a tightly closed container2 stored in a cool2 dry2 !entilated area. Protect against 5hysical damage and moisture. Isolate rom any source o heat or ignition. A!oid storage on "ood oors. e5arate rom incom5ati>les2
com>usti>les2
organic B
or
other
readily
o6idiza>le
Salt content of snack foods
Group number:U11
materials. Protect rom light. ,ontainers o this material may >e hazardous "hen em5ty since they retain 5roduct residues (dust2 solids)D o>ser!e all "arnings and 5recautions listed or the 5roduct.
1irst Aid Measures Inhalation9 &emo!e to resh air. I not >reathing2 gi!e artifcial res5iration. I >reathing is dicult2 gi!e o6ygen. %et medical attention immediately. Ingestion9 I s"allo"ed2 # $ I$#0,E VMII$%. %i!e large Cuantities o "ater. $e!er gi!e anything >y mouth to an unconscious 5erson. %et medical attention immediately. 4in ,ontact9 Immediately ush s4in "ith 5lenty o "ater or at least :7 minutes "hile remo!ing contaminated clothing and shoes. %et medical attention immediately. -ash clothing >eore reuse. horoughly clean shoes >eore reuse. Eye ,ontact9 Immediately ush eyes "ith 5lenty o "ater or at least :7 minutes2 liting lo"er and u55er eyelids occasionally. %et medical attention immediately.
Hazards Identifcation o $itric Acid Emergency !er!ie" Poison' #anger' trong o6idizer. ,ontact "ith other material may cause fre. ,orrosi!e. iCuid and mist cause se!ere >urns to all >ody tissue. May >e atal i s"allo"ed or inhaled. 4in turns yello" on contact and may 5eel o=. %reat care should >e ta4en "hen handling concentrated acid
o6icological Inormation $itric acid9 Inhalation rat ,789 FF 55m ($)
Potential Health E=ects $itric acid is e6tremely hazardousD it is corrosi!e2 reacti!e2 an o6idizer2 and a 5oison. Inhalation9 C
Salt content of snack foods
Group number:U11
,orrosi!e' Inhalation o !a5ors can cause >reathing diculties and lead to 5neumonia and 5ulmonary edema2 "hich may >e atal. ther sym5toms may include coughing2 cho4ing2 and irritation o the nose2 throat2 and res5iratory tract. Ingestion9 ,orrosi!e' "allo"ing nitric acid can cause immediate 5ain and >urns o the mouth2 throat2 eso5hagus and gastrointestinal tract. 4in ,ontact9 ,orrosi!e' ,an cause redness2 5ain2 and se!ere s4in >urns. ,oncentrated solutions cause dee5 ulcers and stain s4in a yello" or yello">ro"n color. Eye ,ontact9 ,orrosi!e' Va5ors are irritating and may cause damage to the eyes. ,ontact may cause se!ere >urns and 5ermanent eye damage. ,hronic E65osure9 ongterm e65osure to concentrated !a5ors may cause erosion o teeth and lung damage. ongterm e65osures seldom occur due to the corrosi!e 5ro5erties o the acid. Aggra!ation o Pree6isting ,onditions9 Persons "ith 5ree6isting s4in disorders2 eye disease2 or cardio5ulmonary diseases may >e more susce5ti>le to the e=ects o this su>stance.
Handling and torage tore in a cool2 dry2 !entilated storage area "ith acid resistant oors and good drainage. Protect rom 5hysical damage. 3ee5 out o direct sunlight and a"ay rom heat2 "ater2 and incom5ati>le materials. #o not "ash out container and use it or other 5ur5oses. -hen diluting2 the acid should al"ays >e added slo"ly to "ater and in small amounts. $e!er use hot "ater and ne!er add "ater to the acid. -ater added to acid can cause uncontrolled >oiling and s5lashing. ,ontainers o this material may >e hazardous "hen em5ty since they retain 5roduct residues (!a5ors2 liCuid)D o>ser!e all "arnings and 5recautions listed or the 5roduct.
1irst Aid Measures Immediate frst aid treatment reduces the health e=ects o this su>stance. 1;
Salt content of snack foods
Group number:U11
Inhalation9 &emo!e to resh air. I not >reathing2 gi!e artifcial res5iration. I >reathing is dicult2 gi!e o6ygen. ,all a 5hysician. Ingestion9 # $ I$#0,E VMII$%' %i!e large Cuantities o "ater or mil4 i a!aila>le. $e!er gi!e anything >y mouth to an unconscious 5erson. %et medical attention immediately. 4in ,ontact9 In case o contact2 immediately ush s4in "ith 5lenty o "ater or at least :7 minutes "hile remo!ing contaminated clothing and shoes. -ash clothing >eore reuse. horoughly clean shoes >eore reuse. %et medical attention immediately. Eye ,ontact9 Immediately ush eyes "ith 5lenty o "ater or at least :7 minutes2 liting lo"er and u55er eyelids occasionally. %et medical attention immediately.
Remarks
1. Snacks such as potato chips should not be grinded as the filtration of the solution mixture takes a long time to complete. $nstead% hot &ater can be used to dissol/e the chloride ions of the samples. #. "utrition information regarding sodium content may be pro/ided on labels of some snack packages. The information can be used to estimate the /olume of titrant. Typical salt content of potato chip is around 1 g sodium per 1;; g sample. Procedure
A.Mohr Method Determination of Chloride Content of Potato Chips
1. @eigh accurately approximate 1; g of potato chips in a #<; cm beaker% then add about 1#< cm of hot distilled &ater into the beaker. #. Stir the mixture carefully for ; s% &ait for 1 minute% stir again for ; s% then let it cool do&n to room temperature. . !ilter the solution through glass &ool. Transfer the filtrate to a #<; cm /olumetric flask and make it up to the mark &ith distilled &ater. -. Using a pipette% transfer #<.; cm of the filtered solution to a #<; cm conical flask. 'dd 1 cm of <= potassium chromate)V$+ indicator to the solution. 11
Salt content of snack foods
Group number:U11
<. Titrate the solution &ith standard ;.1 M 'g", to the first /isible pale reddish bro&n colour of sil/er chromate)V$+ that persists for ; s. The potassium chromate)V$+ indicator initially gi/es a cloudy solution of a faint lemonyello& colour. 2ecord the /olume of titrant used. >. 2epeat the titration t&o to three times to obtain concordant results.
xperimental Set!up
B. Volhard Method Part A" Standardisation of #$#% M Potassium Thiocyanate Solution
AS" is a /ery deli*uescent solid. Standardisation &ith standard sil/er nitrate solution is re*uired to determine the concentration of the AS" solution prepared. 1. ipette 1;.; cm of standard ;.1 M sil/er nitrate solutions to a 1#< cm conical flask. 'dd < cm of 1:1 nitric acid and 1 cm of ammonium iron)$$$+ sulphate solution as indicator. #. Titrate &ith potassium thiocyanate solution% s&irl the solution constantly until the reddish bro&n colour begins to spread throughout the solution. . Then add potassium thiocyanate solution drop&ise% s haking the solution thoroughly bet&een additions of drops. The end point is the first appearance of a dark red colour due to the presence of iron)$$$+ thiocyanate complex. This is more easily seen if the precipitate is allo&ed to settle after each addition near the end point. 9esides% it &ill be helpful to compare the colour &ith a 1#
Salt content of snack foods
Group number:U11
solution made by adding < cm of >M nitric acid and # cm of ammonium iron)$$$+ sulphate indicator to 4< cm of &ater. 2ecord the /olume of titrant used. -. 2epeat the titration t&o to three times to obtain concordant results. Part &" Determination of Chloride Content of Potato Chips
1. @eigh accurately approximate 1; g of potato chips in a #<; cm beaker% then add about 1#< cm of hot distilled &ater into the beaker. #. Stir the mixture carefully for ; s% &ait for 1 minute% stir again for ; s% then let it cool do&n to room temperature. !ilter the solution through glass &ool into a #<; cm conical flask. . 'dd <;.; cm of ;.1 M 'g", )a*+ to the filtrate% and then < cm of 1:1 nitric acid into the conical flask. Stopper the flask &ith a rubber bung and shake until the precipitated sil/er chloride settles% lea/ing a clear supernatant li*uid. -. !ilter the solution through a piece of dry filter paper )the solution must be filtered because sil/er chloride is more soluble than sil/er thiocyanate and tends to react &ith iron)$$$+ thiocyanate.+. Transfer the filtrate to a #<; cm /olumetric flask and make it up to the mark &ith distilled &ater. <. Using a pipette% transfer <;.; cm of the filtrate solution into a conical flask% add 1 cm of saturated ammonium iron)$$$+ sulphate indicator and titrate the excess sil/er nitrate &ith ;.;< M potassium thiocyanate solution. The end point is the first appearance of a dark red colour due to the iron)$$$+ thiocyanate complex. 2ecord the /olume of titrant used. >. 2epeat the titration t&o to three times to obtain concordant results. xperimental Set!up
1
Salt content of snack foods
Group number:U11
xpected results
A. Mohr Method The end point changes from pale yellow to persists pale reddish
brown.
B. Volhard Method Part A" Standardisation of #$#% M Potassium Thiocyanate Solution
The end point changes from reddish bro&n to dark red complex. Part &" Determination of Chloride Content of Potato Chips
The end point changes from reddish bro&n to dirty green..
1indings Mass of potato chips used:
A. Mohr Method Burette readings9 itration no.
rial
Final reading(cm3) Initial reading(cm3) Volume used(cm3)
B. Volhard Method
1-
G
Salt content of snack foods
Group number:U11
Part A" Standardisation of #$#% M Potassium Thiocyanate Solution
Burette readings9 itration no.
rial
G
Final reading(cm3) Initial reading(cm3) Volume used(cm3)
Part &" Determination of Chloride Content of Potato Chips
Burette readings9 itration no.
rial
Final reading(cm3) Initial reading(cm3) Volume used(cm3)
1<
G
