The Effect of Sodium Carbonate on Hard Water

The Effect of Sodium Carbonate on Hard Water

Length: 3102 words (8.9 double-spaced pages)

Rating: Excellent

Open Document

Essay Preview

More ↓
The Effect of Sodium Carbonate on Hard Water


Aim
===

In this experiment, we aim to investigate the effect of sodium
carbonate on hard water.



Method
======

Firstly, 25.00cm3 of a sample of water was pipetted into a clean
conical flask. The pipette was used because this measures and delivers
a very accurate amount of liquid (to the nearest hundredth of a cm3,
or 0.01cm3), but care had to taken to make sure it was not held by the
bulge, as this could have made the amount inaccurate (as body
temperature heats the apparatus up and makes it expand). Also, the
pipette is used to avoid spillage, as the thin tube can put the water
straight into the appropriate container. Furthermore, a pipette filler
was used for safety purposes, because blowing or sucking could get
unwanted and potentially dangerous substances into the mouth. 0.500g
of sodium carbonate (a white powder) was added to the water, having
been carefully weighed on an electronic balance - this was very exact
and had a cover to maximise accuracy (it protected the balance from
being affected by wind or other particles). The balance measured the
mass of the powder to the nearest thousandth of a gram (i.e. 0.001g).
Then a burette on a stand was obtained, a considerable amount of soap
solution funnelled into it through the top (so the level reached near
the top) and 1cm3 of the solution added to the water. The burette
(glass tube with measurements marked on the side and a stopcock at the
bottom) was used because it very accurately lets out 1cm3 every time.
The conical flask was then corked (so no substances were able to
escape through the top) and shaken for ten seconds (this timed by a
stop-watch). It was observed whether a permanent lather (one that
lasted for more than ten seconds - again a stop-watch was used) was
created. If so, the result of 1cm3 being added was recorded. If not,
then the process of adding a cm3 of soap solution and shaking the

How to Cite this Page

MLA Citation:
"The Effect of Sodium Carbonate on Hard Water." 123HelpMe.com. 24 Aug 2019
    <https://www.123helpme.com/view.asp?id=122096>.

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »

Essay about Softening Hard Water With Sodium Carbonate

- Softening Hard Water With Sodium Carbonate Prediction ---------- In a preliminary experiment, we discovered that adding 1g. Na2CO3 to hard water softened it slightly. We tested both tap water and distilled water with the sodium stearate and discovered that tap water was far harder than distilled water, we then tested tap water that 1g of Na2CO3 had been applied to. This solution was softer than the original tap water. The exact results were; Type of water Soap solution required 1st attempt 2nd attempt Average Distilled 0.5 0.5 0.5 Tap 4.5 5.0 4.75 Tap with 1g....   [tags: Chemisty Lab Report]

Free Essays
1567 words (4.5 pages)

Sodium And Its Effect On The Earth Essay

- Sodium was first discovered and isolated by Sir Humphry Davy in 1807. Sodium is located in column 1 of the periodic table where all other alkali earth metals, which all of them have only 1 electron which it would happily give to another element that wants it so that it could be “happy” this then creates a positively charge atom also known as a cation. You could also find sodium by knowing its electron configuration which is [Ne] 3s1. Sodium physical properties are that it is silver in color and is a soft metal, so soft that in its pure form it could be cut with a knife....   [tags: Sodium chloride, Sodium, Chlorine]

Research Papers
1650 words (4.7 pages)

An Investigation into the Effect of Light Intensity on the Rate of Photosynthesis on a Piece of Elodea

- An Investigation into the Effect of Light Intensity on the Rate of Photosynthesis on a Piece of Elodea Plan: Method: 1) First I will put some water into a boiling tube and add 5 spatulas of Sodium Hydrogen Carbonate. I will add 5 spatulas of Sodium Hydrogen Carbonate as it reacts with water and forms carbon dioxide; also I have so much so that I have carbon dioxide in excess. 2) Then I will cut off 5cm of elodea and place it into the boiling tube. 3) Thirdly I will place the boiling tube in a test tube holder 5cm in front of the light source....   [tags: Papers]

Free Essays
1510 words (4.3 pages)

The Effect Of Sodium Diet On Nutrition Foundation Essay

- Introduction: Salt is the topic and there is lots of evidence that too much salt, which is sodium in your diet is dangerous for your health according to NZ Nutrition Foundation (2013) this is because a high sodium diet will increase your chances of getting high blood pressure, heart disease, stroke, and kidney disease. The World Health Organisation has a requirement to reduce at people consume because it is confirmed that Sodium is a contributor to early deaths globally according to the World Health Organisation (2013)....   [tags: Nutrition, Hypertension, New Zealand, Supermarket]

Research Papers
1217 words (3.5 pages)

Determining the Concentration of a Sodium Carbonate Solution Essay

- Determining the Concentration of a Sodium Carbonate Solution Calculating the quantities and the concentration of the reagents Sodium Carbonate + Hydrochloric acidà Sodium Chloride + Carbon Dioxide + Water Na CO + 2HCL à 2NaCl + CO +H O Calculating the approximate concentration of the sodium carbonate solution (mol dm ³) Approx = 5 5 = 0.0472mol dm ³ Concentration Mr 46+12+48 The approximate concentration of Sodium Carbonate is 0.0472mol dm ³ If the HCl needs to be twice as big as the alkali it needs to be multip...   [tags: Papers]

Free Essays
581 words (1.7 pages)

The Concentration Of Sodium Chloride Increases Essays

- If the mass of sodium chloride increases, then the growth in the length of the embryo root decreases. This is because the greater the concentration, the less imbibition for the bean to absorb water for metabolic reaction. Since beans has hormones that inhibits bean germination, it requires a water to wash away the hormone for germination to occur. As more sodium chloride is dissolved in the water, the table salt inhibits imbibition so the hormone is remained within the bean. Additionally, once the bean stops germination, the presence of oxygen is meaningless even though aerobic cell respiration occurs in germination to generate a net yield of 38 ATP per glucose....   [tags: Sodium chloride, Water, Salt, Sodium]

Research Papers
1569 words (4.5 pages)

Essay on The Effect of Sodium Chloride on a Potato Chip

- The Effect of Sodium Chloride on a Potato Chip To investigate what happens to a potato chip's weight when placed in different concentrations of Sodium Chloride INTRODUCTION:~ ============== Osmosis is defined as 'the movement of water molecules from an area of high water concentration to an area of low water concentration, across a semi-permeable membrane' (Collins, 1999). A semi-permeable membrane is a membrane that partially allows liquid to pass through. In the case of the experiment I am carrying out, the potato chips have small holes in their membranes, which only lets some water molecules flow in and out of the solution and potato chips depending o...   [tags: Papers]

Free Essays
1591 words (4.5 pages)

Essay on The Effect of Acid on Sodium Thiosulphate

- The Effect of Acid on Sodium Thiosulphate Aim: My Aim is to see how concentration of acid will affect the time it takes for Sodium Thiosulphate to become cloudy and make a cross below it to disappear. Method: Apparatus Hydrochloric Acid Sodium Thiosulphate Distilled Water 250cm ³ Beaker- I need a beaker big enough to see the cross and although the 100cm³ would be perfect volume wise I would prefer to use a bigger one so I can fit the cross under it and also be able to pour the reactants into it without any spillage 100cm ³ Measuring Cylinder- I have decided to use this cylinder for the Sodium Thiosulphate....   [tags: Papers]

Free Essays
2273 words (6.5 pages)

Sodium Thiosulphate's Effect on the Rate of Reaction with Hydrochloric Acid

- Sodium Thiosulphate's Effect on the Rate of Reaction with Hydrochloric Acid Aim: I am going to investigate how varying the concentration of Sodium Thiosulphate affects the rate of reaction with Hydrochloric Acid. Prediction: The equation for the reaction is: [IMAGE] Sodium Thiosulphate + Hydrochloric Acid Sodium Chloride + Water + Sulphur + Sulphur dioxide [IMAGE] Or: Na2S2O3 + 2HCl S + 2NaCl + H2O + SO2 This reaction has a definite end point (when the cross on the test tube 'disappears')....   [tags: Papers]

Free Essays
1455 words (4.2 pages)

Essay on Sodium

- Life could not exist without compounds of sodium. These compounds hold water in body tissues, and a severe deficiency of sodium can cause death. Blood contains sodium compounds in solution. Sodium compounds are used in industry in the manufacture of chemicals and pharmaceuticals, in metallurgy, in sodium vapor lamps, and in the production of hundreds of every day products. One of the most common sodium compounds is table salt, or sodium chloride. In its pure form sodium is a silver-white, soft and waxy metallic element....   [tags: essays research papers]

Free Essays
387 words (1.1 pages)

Related Searches

flask was repeated, as many times as necessary to produce a permanent
lather, and the exact amount of solution needed was noted down. The
flask was washed out carefully, once with tap water and duly with
distilled water (so that the apparatus was thoroughly cleaned,
avoiding any contamination). The experiment was promptly repeated all
over again, but this time with other amounts of sodium carbonate
(1.000g, 1.500g, 2.000g, 2.500g), and the results recorded also in a
table (using a tally chart). Afterwards, the different results of the
tests were compared to make out any trends.



Diagrams
========

Prediction

I predict that the more sodium carbonate is added to the water, the
less soap is needed to create a lather. Eventually, though, the powder
will lose its effectiveness, due to the fact that all the calcium ions
will have already been removed. So these are the results I would
expect to obtain, in graph form:

(N.B. The amount of sodium carbonate is on the x-axis because it was
the quantity which we controlled, but the amount of soap solution
needed was the quantity which we were investigating, and was therefore
beyond our control.)

Theory

Now, the explanation of the theory behind the experiment. Soaps are
compounds of sodium or potassium. A common soap, and the one used
here, is sodium stearate (Na+St- where St- = C17H35COO-). Sodium
stearate is soluble in water, but calcium stearate is not. Hard water
contains dissolved calcium ions - Ca2+(aq) - which cause the water to
form 'scum', a solid white precipitate. Hard water also makes soap
very difficult to lather, again because of the calcium ions.

So when soap is mixed with hard water, this is what happens:

sodium stearate + calcium hydrogencarbonate º

(soap) (in hard water)

º calcium stearate + sodium hydrogencarbonate

(scum)

2NaSt(aq) + Ca(HCO3)2(aq) º CaSt2(s) + 2NaHCO3(aq)

The ionic equation for this reaction is:

Ca2+(aq) + 2St-(aq) º CaSt2(s)

(N.B. Only ions which make the scum are shown, not the 'spectator'
ions, such as the ones from 2NaHCO3(aq). Two stearate ions are needed
to remove one calcium ion.)

Instead of calcium hydrogencarbonate, calcium sulphate (CaSO4) could
be written in the equation:

2NaSt + CaSO4 º CaSt2 + Na2SO4

(from soap)(from hard water)(scum)(left in solution)

Therefore, in the experiment, this is what happened once the sodium
carbonate powder (Na2CO3(s))was added:

CaSO4 + Na2CO3 º CaCO3 + Na2SO4

We can see that this is a double-decomposition reaction, with the
sodium 'winning' the sulphate away from the calcium because it is
higher in the reactivity series of elements. So the sodium carbonate
effectively lessens the effect of calcium ions in the water, thus
softening it and making it easier for a lather to be formed.
Therefore, all this must mean that the more sodium carbonate is used,
the more calcium ions are removed, the softer the water is and the
more likely it is for a lather to be created on the surface of the H2O.

The graph (on pg. 3) takes this shape because the more sodium
carbonate is added, the less soap solution it takes to give a
permanent lather (as the water is made softer and softer). The graph
levels off after a certain time, though. This is because eventually
there are no more calcium ions to remove by the sodium carbonate. That
completes my prediction.

But for the experiment to be fair and successful, there are a number
of key factors:

· having the correct amount of sodium carbonate (so it must be weighed
carefully, with no wind interference) - it is accurate to 0.001g (3
decimal places), so is extremely precise;

· having the correct amount of soap solution (so it is made sure that
the burette is used carefully and accurately);

· having the correct amount of water (so the pipette must be used with
great care, and not held by bulge, which renders the amount
inaccurate) - correct to 2 decimal places (to 0.01g), again very
accurate;

· the source of water (so one has to ensure that the same source of
water is being used each time the experiment is repeated);

· the time taken to shake the conical flask (so a stop-watch is used);

· the cleanliness of the apparatus (so the equipment is rinsed out
with normal water and then distilled water, to maximise hygiene and
prevent contamination);

· the temperature of the laboratory (so it is ensured that it remains
the same throughout the duration of the tests).

All these variables can be controlled except the last one - but the
temperature of the laboratory should be the same anyway, so
temperature should not affect the results at all.

Furthermore, there are particular ranges of values which should be
considered in the experiment. In regard to the amounts of sodium
carbonate tested, there should be a minimum of 0.5g and a maximum of
5g, as this certainly provides us with a suitable range to distinguish
any trends in the results. Also, to really have a sufficient total of
results for analysis, no less than five different values of sodium
carbonate should be tested. Moreover, the whole experiment should be
repeated at least once and averages calculated in order to eliminate
any anomalous results which are obtained. So, in essence, one can be
sure that the experiment is producing reliable (by repeating it to
remove fluke results) and accurate (by using the equipment efficiently
and carefully, as well as weighing and measuring out substances
exactly, to several decimal places - the sodium carbonate is weighed
to three decimal places, whilst the water is measured out to two d.p.)
results.

Preliminary Experiments

To verify my prediction, some extra preliminary work was done.

Firstly, many different samples of water (e.g. from the laboratory,
from Norwich, Evian) were tested by a similar process to the one in
this experiment. Same amounts of the types of water were put into
conical flasks (using pipettes) and then the soap solution was poured
into them via the burette. It was recorded how many cm3 were needed to
produce a lather, as in this coursework experiment. These were the
results produced:

Source of sample

Volume of soap for lather (cm3)

Hardness rating

Lab. Tap Water

7

Hard

Distilled Water

1

Very Soft

Norwich Tap Water

9

Very Hard

Evian Water

6

Moderately Hard

Kingston Tap Water

8

Hard

This shows that the calcium ions have the effect of reducing the
amount of lather. This is because the distilled water, which is pure H2O,
with nothing dissolved in it - including calcium ions, was proved to
be very soft (producing a lather very quickly with the soap solution),
whilst the Norwich Tap Water, which has many calcium ions dissolved in
it, was very hard (a lather was made only after much soap solution was
added). All this information allowed me to confirm my prediction that
the more sodium carbonate is used and the more calcium ions can be
removed by it, the faster a lather will be seen and so the softer the
water will be.

Secondly, and more importantly, another preliminary test was
conducted. 25.00cm3 of tapwater was measured out, and 0.500g of sodium
carbonate added to it. Then the process was exactly the same as in the
coursework experiment, but only samples of 0.500g and 2.000g of sodium
carbonate (Na2CO3) were tested, as well as a control with just plain
water being tested.

Mass of Na2CO3 (g)

Volume of soap used (cm3)

0.000

7

0.500

3

2.000

1

I would therefore expect the results to show a similar trend in the
coursework experiment, too, with the hardness being reduced with every
amount of sodium carbonate added, and so less soap solution being
required each time.

2. OBTAINING EVIDENCE

Safety



Here are the safety precautions which we took doing the experiment:
===================================================================

1. The soap solution is flammable, so be careful to not ignite it by
keeping it away from fire.

2. Wear safety spectacles at all times to prevent the soap solution
getting into the eyes.

3. Take care with wet glassware (which is slippery so it could slip
from the hands and smash).

4. Take care with the fragile glass pieces of equipment (to prevent
glass shattering).

5. Use the pipette filler to fill the pipette with water (as blowing
and sucking could get unwanted and potentially dangerous substances
into the body).

6. Hold the pipette near the end where the filler will go.

7. When shaking the conical flask, hold it securely and keep a thumb
over the bung to stop substances escaping from the top of the flask.

8. N.S.P. (normal safety precautions) apply.



Results
=======

Mass of sodium carbonate (g)

Volume of soap solution used

(cm3)

Average

(cm3)

0.000

7.00

6.50

7.00

6.83

0.500

6.00

6.00

6.00

6.00

1.000

5.00

5.50

6.00

5.50

1.500

4.50

5.00

4.50

4.67

2.000

4.00

4.50

3.50

4.00

2.500

3.00

4.00

3.00

3.33

3.000

2.50

2.50

2.50

2.50

3.500

2.00

2.50

1.50

2.00

4.000

1.50

2.00

1.50

1.66

4.500

1.50

1.50

1.50

1.50

5.000

1.50

1.50

1.50

1.50

[N.B. For every individual test, 25.00cm3 of water was used.]

3. ANALYSING AND CONSIDERING EVIDENCE



Analysis
========

In the experiment, it was seen that the more sodium carbonate was
added to the water used, the less soap solution was necessary to
produce a lather. This can be best illustrated by a graph of the
results (see pg. 12).

The graph makes clear some trends in the results obtained. At first,
when the mass of sodium carbonate powder is gradually increased (by
0.500g each time), the amount of soap solution needed to make a lather
steadily decreases. Then, after 3.000g of powder is used, the graph
begins to level off into a plateau, indicating that however much more
sodium carbonate one adds, the quantity of the necessary soap to
produce a lather will remain the same. This is explained below.

Water becomes 'hard' when it is dissolved with calcium (Ca2+) ions (or
magnesium, Mg2+, ions). To soften this water, one has to remove these
ions. One method of removing the calcium ions is to add sodium
carbonate. When the calcium ions (from the water) and the carbonate
ions (from the sodium carbonate) react together, calcium carbonate is
formed:

Ca2+(aq) + CO32-(aq) º CaCO3(s)

And this is the equation with all the ions involved:

CaSO4 (aq) + Na2CO3 (aq) º CaCO3 (s) + Na2SO4 (aq)

(calcium sulphate from hard water)(sodium carbonate)(calcium
carbonate)(sodium sulphate)

So here the sodium 'wins' the sulphate away from the calcium because
it is higher in the reactivity series of elements. The result of the
reaction is that the soap cannot react well with the calcium ions
(because they are 'locked' in the insoluble calcium carbonate), and
thus this makes it more difficult for 'scum' to be formed, and a
lather appears faster. So the sodium carbonate effectively lessens the
effect of calcium ions in the water, thus softening it and making it
easier for a lather to be formed. The calcium carbonate is
precipitated and this removes the hardness from the water. Therefore,
all this must mean that the more sodium carbonate is used, the more
calcium ions are removed, the softer the water is and the more likely
it is for a lather to be created on the surface of the water.

When the soap solution is promptly added to this from the burette, the
whole experiment takes shape. Soaps are compounds of sodium or
potassium. Here, sodium stearate was used. Sodium stearate is soluble
in water, but calcium stearate is not. Hard water contains dissolved
calcium ions which cause the water to form 'scum', a solid white
precipitate. Hard water also makes soap difficult to lather, again
because of the calcium ions. So when soap is mixed with hard water,
this is what happens:

2NaSt + CaSO4 º CaSt2 + Na2SO4

(from soap)(from hard water)(scum)(left in solution)

The ionic equation for this reaction is:

Ca2+(aq) + 2St-(aq) º CaSt2(s)

(N.B. Only ions which make the scum are shown, not the 'spectator'
ions,

such as the ones from Na2SO4. Two stearate ions are needed

to remove one calcium ion.)

Therefore, when the conical flask, in which all the substances used in
this experiment are, is shaken, a combination of factors has to be
considered. By this time, the sodium carbonate powder has served to
soften the water and remove the permanent hardness, by the calcium
ions (the cause of hardness) being combined to form calcium carbonate.
The calcium ions are the ones which cause precipitate formation when
reacting with soap, so by reacting it with the sodium carbonate one
makes it into a substance that does not affect the lathering of water.
As a result, a lather is more likely to appear quicker (i.e. with less
soap) as more sodium carbonate is progressively added - and this is
the trend shown by the results.

However, after 3.000g of sodium carbonate was added, the graph started
to level off into a plateau which would continue at the 1.50 cm3 of
soap solution mark regardless of how much powder was used for the
test. This is because the sodium carbonate loses its effectiveness due
to the fact that all the calcium ions will have already been removed
by it, and so it is just not possible to remove any more, however much
powder is added. Therefore, the amount of soap solution ought to stay
the same, too, as it indeed does, resulting in the graph levelling off
into a plateau.

All this proves that my prediction was quite correct, because I did
rightly predict that the more sodium carbonate was added to the water,
the less soap would be needed to create a lather, and that the graph
of results would even off. On the other hand, my prediction graph
envisaged that line of best-fit would see an initial sharp fall, which
did not actually happen. So it has been proved that as one gradually
increases the quantity of sodium carbonate used, the amount of soap
solution needed to produce a lather also gradually decreases, until
the plateau is reached.

4. evaluating



Evaluation
==========

Overall, the experiment was a success in that it showed what it was
supposed to - that sodium carbonate certainly has a definite effect on
the amount of lather made (the trend clearly and well seen on the
graph, pg. 12), instigating the faster production of it when soap
solution is added. Furthermore, the experiment was efficient and easy
to use, because only one process was carried out at a time, and the
fact that it was done in pairs meant that the tests were conducted
quicker, which resulted in factors (such as temperature) staying
constant throughout most of the experiment. The tests followed a
simple, repetitive process, making them easy to carry out.

The results obtained from the experiment do fit the pattern expected,
allowing the conclusion of 'the more sodium carbonate was added to the
water used, the less soap solution was necessary to produce a lather'
to be backed up by good, reliable evidence. Therefore, the graph shows
that the line of best-fit goes through, or is very close to, the
plotted points, thus showing that indeed as gradually more and more
sodium carbonate powder was used, the amount of soap needed for a
lather to form steadily decreased for the duration of the experiment.
The plateau at the end of the best-fit line also validates a
scientific explanation, confirming that

the sodium carbonate loses its effectiveness because all the calcium
ions will have already been removed by it, and so it is just not
possible to remove any more, however much powder is added (so the
amount of soap for making a lather remains the same). So the results
were highly successful, supporting all the scientific theories very
well; in fact, no totally anomalous results were recorded.

However, the procedure, although producing suitable evidence, was not
perfect. Firstly, there was a problem with temperature. Unfortunately,
the temperature of the laboratory when we conducted the experiment was
beyond our control, and it could have fluctuated and had an effect on
the results in the process. Secondly, the temperature of the water
used for the tests may not have been entirely constant, either. This
was especially true of the start of the experiment on any day, when
warmer water tended to come from the taps than later on - this extra
heat definitely could have had an effect on the results, as it often
plays a major role in affecting the speed of reactions. To combat
this, a thermometer could be used to make sure that water temperature
stays the same, or some water could be allowed to flow out prior to
the experiment, thus making sure that the early warm water does not
affect the tests. Thirdly, students were not totally clear on what
exactly made up a full lather. Although it was seen whether the lather
lasted for ten seconds or more, it was then sometimes still not clear
if the precipitate was thick enough to be a proper lather. This
problem could be overcome by measuring the lather and making sure it
was a certain height (e.g. 0.5cm). Finally, the fact that the
experiment was carried out in sections over the course of a couple of
weeks was a big failure of the experiment, without doubt. Various
conditions could have varied from session to session, so different
parts of the experiment were conducted under different conditions.
This means that the experiment was not very fair, as a different set
of apparatus was used each time the tests were continued from the
previous lesson, and this caused stages of the experiment conducted
differently, and so results not quite matching the exact pattern of
other results could well have been recorded. Therefore, the experiment
should be done on one particular day, or at least every pair of
students should use the same equipment during every session (so it
could be labelled with their names).

The actual results do follow the prediction made closely, and are
certainly good enough to support the conclusion that I have drawn,
with the graph and its line of best-fit clearly demonstrating
unmistakable patterns. Moreover, the slight anomalies seen on the
graph can be easily accounted for. If a point is slightly below the
best-fit line (e.g. the one circled in green on the graph), then less
soap was required to produce a lather than expected for that amount of
sodium carbonate. This may have been because slightly more sodium
carbonate powder was added, so the water was actually a bit softer
than it should have been, so inevitably less soap was needed; also,
this may have been because I was not strict enough on what exactly
constituted a lather, and thus recorded something as being a lather
when it was not actually a full one. If a point is slightly above the
best-fit line (e.g. the one circled in orange on the graph), then more
soap was required to produce a lather than expected for that amount of
sodium carbonate. This may have been again because I was not exactly
sure what a real lather was (it was sometimes hard to distinguish
between a lather and not quite a lather!), or perhaps because more
sodium carbonate powder was added then should have been, so the water
was actually harder than it should have been, and more soap was needed
for a lather to appear. Also, the anomalies could have been recorded
because a different set of equipment was used for different stages -
if, for example, one electronic balance used was slightly inaccurate
(because of damage, say) and another was absolutely accurate, then
minor differences in exact result trends would be seen, and on the
graph these appear as wrong anomalies. This is because, if a
inaccurate amount of sodium carbonate was added, then the water would
become either softer or harder than expected, and so the amount of
soap needed to make a lather would rise or fall accordingly, too.

More work could be done to extend this investigation and thus provide
more support for the conclusion.

Many different samples of water (e.g. distilled, from the laboratory,
from students' homes) could be tested by a similar process to the one
in this experiment. Same amounts of the types of water could be put
into conical flasks (using pipettes) and then the soap solution poured
into them via the burette. It would be recorded how many cubic
centimetres were needed to produce a lather, as in this coursework
experiment. This would show that the calcium ions have the effect of
reducing the amount of lather. This is because the distilled water,
which is pure H2O, with nothing dissolved in it (including calcium
ions), would be proved to be very soft (producing a lather very
quickly with the soap solution), whilst another type of water, which
has many calcium ions dissolved in it, would be very hard (a lather
made only after much soap solution was added). All this information
would allow me to confirm my conclusion here that the more sodium
carbonate is used and the more calcium ions can be removed by it, the
faster a lather will be seen and so the softer the water will be.
Return to 123HelpMe.com