Soap and Water

8/19/2019 Soap and Water

1/55

© Boardworks Ltd 20091 of 55


2/55



3/55


The Earth’s water

It is estimated that there are 1,380 million km 3 of water onthe Earth.

Howe er, onl! 3" of the Earth#s water is fresh. $he remainin%9&" is saltwater, and forms the seas and o'eans.


4/55

© Boardworks Ltd 2009( of 55

The water cycle


5/55


Events in the water cycle


6/55

© Boardworks Ltd 2009) of 55

Why is water so important?

*ater is e+tremel! im ortant to life on Earth and is also -sed! h-mans in a wide ran%e of a'ti ities.

transport coolants

washing

solvents

fishing leisure


7/55

© Boardworks Ltd 2009& of 55

How is water treated?

*ater for o-r homes is treated to make it safe for drinkin% !the followin% s!stem/

s- lied tohomes, offi'esand fa'tories

'hlorine added filter eds

settlement tank

'hemi'als added whi'h'om ine with dirt toform a re'i itate

water from reser oir


8/55


Stages in water treatment


9/55


What is desalination?

In some 'o-ntries, there is not eno-%h rainwater to 'olle't inreser oirs. Instead, the ro'ess of desalination is -sed tomake freshwater from seawater.

an !o- think of an! ad anta%es and disad anta%esof desalination

$he sim lest

method ofdesalination isto distil thewater, lea in%the salt ehind.


10/55© Boardworks Ltd 200910 of 55

Why is fluoride added to water?

In some 'o-ntries, fl-oride is added to drinkin% water in theform of he+afl-orosili'i' a'id H

2i4

). In the 67, a o-t 10"

of homes re'ei e water with added fl-oride.

4l-oride has een ro en to stren%then tooth enamel, whi'hhel s to re ent tooth de'a!.

'ientists first made a link etween fl-oride and teeth inthe 1930s. *hat e iden'e do !o- think the! looked at

4l-oride o''-rs nat-rall! in some water s- lies,and is also nat-rall! resent in tea.

ost tooth astes also'ontain added fl-oride.



Should fluoride be added to our water?



Voting: fluoride in drin ing water


14/55© Boardworks Ltd 20091( of 55

!issolving words

If a s- stan'e : e dissol ed it is 'alled ;;;;;;;;;; .

If a s- stan'e ::

an !o- fill in the missin% words in the senten'es elow



the amount of a substance that will dissolve in" dm # of water at $%&' (" dm # ) "*** cm # ) " litre+

What is solubility?

4or e+am le, the sol- ilit! of sodi-m 'hloride is 3)0 %?dm3.

,$+ *hat mass of sodi-m 'hloride wo-ld dissol e in 2 dm 3

of water at 25 @

,#+ *hat mass of sodi-m 'hloride wo-ld dissol e in 500 'm 3 of water at 25 @

,"+ *hat wo-ld ha en if !o- added more than 3)0 % ofsodi-m 'hloride to 1 dm 3 of water

ol- ilit! is defined as/


16/55© Boardworks Ltd 20091) of 55

-nvestigating solubility

n e+ eriment was 'arried o-t to determine the sol- ilit! of an-m er of solid 'hlorides. Here are the res-lts/

How 'an !o- -se the res-lts to 'al'-late the sol- ilit! in %?dm 3 of ea'h solid

200 'm 3'u'l $

chloride volume ofwater

.g'l $/'l

0a'l

1n'l $

mass of chloridethat dissolved

151 %

80 %30 %

&2 %

)18 %

150 'm 3

100 'm 3

200 'm 3

150 'm3


17/55© Boardworks Ltd 20091& of 55

'alculating solubility



Which chloride is the most soluble?



Solubility and temperature

$he sol- ilit! of a s- stan'e de ends on the tem erat-re ofthe sol ent. $his ta le s-mmarises the effe't of tem erat-reon the sol- ilit! of fo-r different solids/

1)&0

otassi-m 'hloride

temperature

0 @ 20 @ (0 @ )0 @ 80 @

sodi-m 'hloride

sodi-m nitrateotassi-m nitrate

solid:

139 31) )13 10)0

280 3(2 (01 (58 513

35& 359 3)( 3&1 380

&30 8&) 1020 1220 1(80

solubility (g2dm #+

How wo-ld !o- 'arr! o-t this e+ eriment



Solubility and temperature graph



Saturation and crystalli3ation

ol-tions e'ome supersaturated when the! 'ontain moresol-te than the! wo-ld normall! e a le to dissol e.

$he sol-te will sta! in sol-tion-ntil a Aseed# 'r!stal is added.$his 'a-ses it to 'r!stalli e o-t ofthe sol-tion er! C-i'kl!.

*hen it does this, it %i es o-theat ener%!.

$his 'an ha en when a sat-ratedsol-tion is 'ooled, or another'han%e in 'onditions o''-rs that

'a-ses sol- ilit! to de'rease.



Solubility of gases

an! %ases are sol- lein water. 4or e+am le,fish 'an reathe

e'a-se of the o+!%endissol ed in water.

4i ! drinks 'ontain'ar on dio+ide that has

een dissol ed intothem -nder ress-re.

*hen the ress-re inside the 'ontainer is released, the'ar on dio+ide %as 'omes o-t of the sol-tion, rod-'in%fi ! - les.



Solubility of gases and temperature

*hat ha ens to the sol- ilit! of %ases as the tem erat-rein'reases

'ar on dio+ide 3.35 1.)9 0.&)

nitro%en

temperature

0 @ 20 @ 50 @

o+!%en

gas:

0.029 0.019 0.012

0.0)9 0.0(3 0.02&

solubility (g2dm #+

If !o- lea e a %lass of lemonade for a few da!s, it %oes flat.

If !o- left one %lass of lemonade in the frid%e and anothereside the radiator, whi'h is likel! to %o flat first


24/55© Boardworks Ltd 20092( of 55

Solubility of o4ygen

s the tem erat-re of water in'reases, the sol- ilit! ofo+!%en de'reases.

$his 'an e a ro lem for fish li in%in ri ers near fa'tories.

In ind-str!, water is often -sed tokee ma'hiner! 'ool. $his rod-'eswarm waste water whi'h then flowso-t into near ! ri ers.

ltho-%h the water is 'lean, it 'anstill affe't aC-ati' animals. $he warmwater 'ontains less of the dissol edo+!%en that fish need to reathe.



Solubility of o4ygen

team of s'ientists in esti%ated the tem erat-re and le elsof dissol ed o+!%en at different oints alon% a ri er.

6 stream of the fa'tor!/ D$hewater is 'ool and 'lean, with lotsof dissol ed o+!%en, and lent!of small in erte rates and fish.

Fownstream of the fa'tor!/ D$hewater is 'lean, -t warm. *e

fo-nd a few dead fish in the ri er.

*hat 'an e done ! the fa'tor! owners to sol e the ro lem


26/55© Boardworks Ltd 20092) of 55

'arbon dio4ide and the ocean

ar on dio+ide is er! sol- le in water, and s'ientists elie ethat a o-t a third of the 'ar on dio+ide rod-'ed ! -rnin%fossil f-els dissol es into the o'eans.

'5 $

sedimentation

carbonate organic carbon

circulation


27/55© Boardworks Ltd 20092& of 55

Solubility of carbon dio4ide

ome s'ientists ha e s-%%estedthat the o'eans 'o-ld a't as aD'ar on dio+ide reser oir toremo e it from the atmos here.

Howe er, if %lo al warmin%

'ontin-es and the o'eans %etwarmer, what will ha en tothe amo-nt of 'ar on dio+idedissol ed in the o'eans

$he %as 'o-ld e -m ed downto the ottom of the o'ean andDstored there.

< 2 is a %reenho-se %as.



Solubility: true or false?


29/55



30/55


What is hard water?


31/55


6sing hard and soft water

oft water forms a lather easil! with soa .

Hard water needs moresoa to form a lather,addin% additional 'ost to'leanin% ro'esses.

How 'o-ld !o- test watersam les to see if the! arehard or soft

$his is e'a-sedissol ed 'hemi'als inthe hard water rea't withsoa to form a s'-m.


32/55


What is hard water?

Hard water 'ontains dissol ed 'al'i-m and ma%nesi-m'om o-nds s-'h as/

ma%nesi-m h!dro%en 'ar onate G % H < 3 2'al'i-m h!dro%en 'ar onate G a H < 3 2ma%nesi-m s-lfate G % < ('al'i-m s-lfate G a < (

Hard water 'an e tem orar! or ermanent.

7ermanent hard water 'ontains ma%nesi-m s-lfate and'al'i-m s-lfate.

Temporary hard water 'ontains ma%nesi-m h!dro%en

'ar onate and 'al'i-m h!dro%en 'ar onate.

d h l


33/55


Hard water chemicals

d d


34/55


Hard water and soap

ainwater e'omes sli%htl! a'idi' as 'ar on dio+ide fromthe air dissol es in it, formin% 'ar oni' a'id.Limestone 'ontains 'al'i-m 'ar onate. s the sli%htl! a'idi'rainwater tri'kles thro-%h ro'ks, the 'al'i-m 'ar onaterea'ts to form sol- le 'al'i-m h!dro%en 'ar onate/

8 8 8carbonicacid

H$'5 # (a9+

calciumcarbonate

'a'5 # (s+

calcium hydrogencarbonate

'a(H'5 #+$ (a9+

carbondio4ide

'5 $ (g+

water

H$5 (l+8 8 8


35/55


How does hard water react with soap?

oa As'-m# is formed ! the rea'tion/

$he soa will onl! form a lather when all the dissol ed'al'i-m h!dro%en 'ar onate in the water has rea'ted.

sodiumstearate

$' " H#%'550a (s+ $0aH'5 # (a9+(' " H#%'55+ $'a (s+

calciumhydrogencarbonate

'a(H'5 #+$ (a9+

8 calciumstearate

sodiumhydrogencarbonate

8

8 8

6sin% hard water 'an 'a-se ro lems/

ore soa is needed to %et a lather.

It 'an e diffi'-lt to 'lean the s'-m from atht- s and sinks.

Hard water 'an e -ns-ita le for ind-strial ro'esseslike d!in%.

i l


36/55

© Boardworks Ltd 20093) of 55

;imescale

*hen hard water is heated, the dissol ed 'al'i-m h!dro%en'ar onate de'om oses to form solid 'al'i-m 'ar onate.

$hese de osits of 'al'i-m 'ar onate are 'alled limescale .

Limes'ale 'an lo'k i es and 'oatthe heatin% elements in kettles,

washin% ma'hines and heaters.

8

8

calcium hydrogencarbonate

'a(H'5 #+$ (a9+

calciumcarbonate

'a'5 # (s+

water

H$5 (l+

carbon dio4ide

'5 $ (g+

8

8

Limes'ale is a oor heat 'ond-'tor, andred-'es the effi'ien'! of a lian'es.


37/55

Wh t th b fit f h d t ?


38/55


What are the benefits of hard water?

Hard water 'an e %ood for health/

'al'i-m is needed for health!ones and teeth

ma%nesi-m is needed for effe'ti emeta olism.

ome st-dies ha e also shown thateo le li in% in hard water areas areless likel! to s-ffer from heart disease.

$he *orld Health


39/55


Softening temporary hard water

$em orar! hard water 'ontains 'al'i-m h!dro%en 'ar onate.

$his is relati el! eas! to remo e, e'a-se it de'om oses onheatin% to form solid 'al'i-m 'ar onate/

7nowin% this, how wo-ld !o- remo e the solid 'al'i-m'ar onate from the water

*hat wo-ld e left ehind after remo in% tem orar!hardness -sin% this method

8

8

calcium hydrogen

carbonate'a(H'5 #+$ (a9+

calcium

carbonate'a'5 # (s+

water

H$5 (l+

carbon dio4ide

'5 $ (g+

8

8

S ft i g h d t


40/55

© Boardworks Ltd 2009(0 of 55

Softening hard water

Both tem orar! and ermanent hard water 'an e softened! addin% sodi-m 'ar onate washin% soda .

$he sodi-m 'ar onate rea'ts with the 'al'i-m 'om o-nds inthe water to form 'al'i-m 'ar onate and sol- le sodi-m'om o-nds, whi'h do not 'ontri -te to hardness/

8 8calcium

hydrogencarbonate

'a(H'5 #+$ (a9+

sodiumcarbonate

0a $'5 # (s+

calciumcarbonate

'a'5 # (s+

sodiumhydrogencarbonate

$0aH'5 # (a9+8 8

*hat is the word and s!m ol eC-ation for the rea'tionetween 'al'i-m s-lfate whi'h 'a-ses ermanent

hardness and sodi-m 'ar onate

S ft i g h d t


41/55


Softening hard water

Hard water: summary


42/55


Hard water: summary


43/55


What is soap?


44/55

© Boardworks Ltd 2009(( of 55

water

oil

soap molecule

What is soap?

If oil is added to water, the two liC-ids do not mi+.

Be'a-se of this, %rease stains 'an e diffi'-lt to remo ed-rin% washin%.

oa s are 'om o-nds

whi'h a't as emulsifiers .

$his means that the!hel the oil to mi+with the water.

How do soaps wor ?


45/55


How do soaps wor ?

How are soaps made?


46/55

© Boardworks Ltd 2009() of 55

How are soaps made?

oa s are -s-all! made from e%eta le fats and oils.$hese 'onsist of 3 fatt! a'id 'hains, held to%ether ! a%l!'erol mole'-le.

$he rea'tion -sed to make soa from fats and oils is'alled saponification .


47/55

What are soapless detergents?


48/55


What are soapless detergents?

oa less deter%ents 'an e made from 'r-de oil, rather thane%eta le oils or animal fats.

sodium octadecylsulfonate

h!dro ho i' end intera'tswith oil mole'-les

h!dro hili' end intera'tswith water mole'-les

oa less deter%ents are still made of lon%, h!dro ho i''ar on 'hains, -t the h!dro hili' end of the mole'-le is as-lfonate/

Soaps vs= soapless detergents


49/55


Soaps vs= soapless detergents

*hat are the ad anta%es and disad anta%es of soa lessdeter%ents o er soa s

oa s form a s'-m with hard water, meanin% that it ismore diffi'-lt to rod-'e a lather. oa less deter%entsrea't with the s- stan'es in hard water to form sol- le'om o-nds, and so do not form a s'-m.

oa less deter%ents 'an e made from the !J rod-'tsof the oil refinin% ro'ess, so 'an e 'hea er to rod-'ethan soa s.

ome soa less deter%ents are not iode%rada le.$his means that the! sta! in the water s!stem 'a-sin%froth in ri ers and streams.

>iological and non biological detergents


50/55


>iological and non biological detergents

Biolo%i'al deter%entsare soa lessdeter%ents that'ontain en !mes.

$he en !mes

are -sed to reakdown 'hemi'als,e.%. in stains on'lothes.

:onJ iolo%i'al deter%ents do not 'ontain en !mes, -t K-strel! on the a'tion of the deter%ent to remo e %rease andstains from items.

@dvantage or disadvantage?


51/55


@dvantage or disadvantage?


52/55


Alossary


53/55


Alossary

@nagrams


54/55


@nagrams

ultiple choice 9ui3


55/55

.ultiple choice 9ui3

Documents

Soap and Water