How Much Salt is in Ocean Water?. Purpose To determine how many mL of salt there is in 200mL of ocean water. To determine how many mL of salt there is

How Much Salt is How Much Salt is in in

Ocean Water?Ocean Water?

PurposePurpose

• To determine how many mL of salt To determine how many mL of salt there is in 200mL of ocean water.there is in 200mL of ocean water.

HypothesisHypothesis

• I think that there will be 6mL of salt I think that there will be 6mL of salt in the 200mL of ocean water. I tried a in the 200mL of ocean water. I tried a taste test before the mixtures went taste test before the mixtures went into the freezer.into the freezer.

MaterialsMaterials

• A sample of ocean waterA sample of ocean water• Small plastic cups/markerSmall plastic cups/marker• Measuring cupMeasuring cup• Table saltTable salt• ThermometerThermometer• FreezerFreezer• TeaspoonTeaspoon• Tap waterTap water• Syringe (to measure salt)Syringe (to measure salt)

ProcedureProcedure

1.1. Get a sample of ocean water, and a sample of tap water.Get a sample of ocean water, and a sample of tap water.2.2. Allow water to stand for 24 hours to achieve room Allow water to stand for 24 hours to achieve room

temperature.temperature.3.3. Number eight plastic cups and label the salt content as Number eight plastic cups and label the salt content as

0, 2, 4, 6, 8, 10, 12, and ocean water. 0, 2, 4, 6, 8, 10, 12, and ocean water. 4.4. Then measure out the amounts of salt and put the Then measure out the amounts of salt and put the

correct amount in each cup.correct amount in each cup.5.5. Pour 200mL of tap water into cups 1-7. Put 200mL of Pour 200mL of tap water into cups 1-7. Put 200mL of

ocean water in cup 8.ocean water in cup 8.6.6. Now, place the cups in a row in the same section of the Now, place the cups in a row in the same section of the

freezer, and make sure there aren’t other items around freezer, and make sure there aren’t other items around them.them.

7.7. Every 10 minutes, check the mixtures to see if there are Every 10 minutes, check the mixtures to see if there are any signs of freezing, and when there is, check the any signs of freezing, and when there is, check the mixtures every 5 minutes until the tops of the mixtures mixtures every 5 minutes until the tops of the mixtures are frozen.are frozen.

8.8. Repeat steps 4-7 two more times.Repeat steps 4-7 two more times.

VariablesVariables Manipulated Variable:Manipulated Variable: the amount of salt in each the amount of salt in each

cup.cup.

Responding Variable:Responding Variable: the time it takes for the the time it takes for the mixtures to freeze.mixtures to freeze.

Control Variables:Control Variables:1.1. The temperature of the freezer (-18 C)The temperature of the freezer (-18 C)2.2. Initial temperature of the mixtures (18 C)Initial temperature of the mixtures (18 C)3.3. The type of cups used in the experiment.The type of cups used in the experiment.4.4. Type of salt (table salt) Type of salt (table salt) 5.5. The placement of the cups in the freezer. (Placed in a The placement of the cups in the freezer. (Placed in a

row in the very back of the freezer)row in the very back of the freezer)6.6. Amount of water in each cup.Amount of water in each cup.

ObservationsObservations

The 12mL of salt mixture and the The 12mL of salt mixture and the ocean water look almost identical ocean water look almost identical when starting to freeze.when starting to freeze.

The cups with salt in them crystallize The cups with salt in them crystallize before they freeze.before they freeze.

After the mixtures crystallize, they After the mixtures crystallize, they turn slushy, and then slowly harden. turn slushy, and then slowly harden.

Results: Trial 1Results: Trial 1Cup #Cup # Amount Amount

Of Salt Of Salt 10 mins.10 mins. 20 mins. 20 mins. 30 mins.30 mins. 40 mins.40 mins. 45 mins.45 mins. 50 mins.50 mins.

#1#1 NoneNone NothingNothing Frost on Frost on the cupthe cup

Starting Starting to Freezeto Freeze

In process In process of freezingof freezing

FrozenFrozen --

#2#2 2mL2mL NothingNothing Frost on Frost on the cupthe cup



FrozenFrozen --




FreezingFreezing In process In process of freezingof freezing


NothingNothing NothingNothing Starting to Starting to FreezeFreeze



NothingNothing NothingNothing Starting to Starting to FreezeFreeze

Crystals Crystals and slushyand slushy


NothingNothing Crystals Crystals and slushyand slushy




NothingNothing NothingNothing NothingNothing NothingNothing

#8#8 Ocean Ocean WaterWater

NothingNothing Frost on Frost on the cupthe cup

NothingNothing NothingNothing NothingNothing Starting to Starting to FreezeFreeze

Results: Trial 1 Results: Trial 1 (continued)(continued)

Cup #Cup # Amount Amount of Saltof Salt

55 mins.55 mins. 60 mins.60 mins. 65 mins.65 mins. 70 mins.70 mins. 75 mins.75 mins. 80mins.80mins.

#1#1 NoneNone -- -- -- -- -- --

#2#2 2mL2mL -- -- -- -- -- --

#3#3 4mL4mL Close to Close to frozenfrozen

FrozenFrozen -- -- -- --

#4#4 6mL6mL Close to Close to frozenfrozen

Close to Close to frozen and frozen and

slushyslushy

Slush is Slush is hardeninghardening

Almost Almost frozenfrozen

FrozenFrozen --

#5#5 8mL8mL SlushySlushy SlushySlushy Slush is Slush is hardeninghardening

Close to Close to FrozenFrozen


FrozenFrozen







SlushySlushy Close to Close to FrozenFrozen


Crystals Crystals and slushand slush

slushyslushy Slush is Slush is hardeninghardening


A little A little SlushySlushy



Cup #Cup # Amount Amount Of Salt Of Salt

85 85 mins.mins.

90 90 mins.mins.

#1#1 NoneNone -- --

#2#2 2mL2mL -- --

#3#3 4mL4mL -- --

#4#4 6mL6mL -- --

#5#5 8mL8mL -- --

#6#6 10mL10mL FrozenFrozen --

#7#7 12mL12mL Not quite Not quite FrozenFrozen

FrozenFrozen


FrozenFrozen --


Of Salt Of Salt 10 mins.10 mins. 20 mins. 20 mins. 30 mins.30 mins. 35 mins.35 mins. 40 mins.40 mins. 45 45

mins.mins.

#1#1 NoneNone NothingNothing NothingNothing NothingNothing Starting to Starting to FreezeFreeze


FrozenFrozen

#2#2 2mL2mL NothingNothing NothingNothing Starting to Starting to FreezeFreeze

Starting to Starting to FreezeFreeze

FrozenFrozen --

#3#3 4mL4mL NothingNothing NothingNothing NothingNothing Starting to Starting to FreezeFreeze


In In process process

of of FreezinFreezin

gg





gg

#5#5 8mL8mL NothingNothing NothingNothing NothingNothing NothingNothing Starting to Starting to FreezeFreeze



gg


NothingNothing In In process process


gg

#7#7 12mL12mL NothingNothing NothingNothing NothingNothing NothingNothing NothingNothing NothingNothing


NothingNothing NothingNothing NothingNothing Starting to Starting to FreezeFreeze




gg


Cup Cup ##

Amount Amount of Saltof Salt

55 55 mins.mins.

60 60 mins.mins.

65 65 mins.mins.

70 70 mins.mins.

75 75 mins.mins.

80mins.80mins.

#1#1 NoneNone -- -- -- -- -- --

#2#2 2mL2mL -- -- -- -- -- --

#3#3 4mL4mL In In process process

of of FreezingFreezing




SlushySlushy SlushySlushy FrozenFrozen -- --



SlushySlushy SlushySlushy SlushySlushy FrozenFrozen --



SlushySlushy SlushySlushy SlushySlushy SlushySlushy SlushySlushy

#7#7 12mL12mL NothingNothing SlushySlushy SlushySlushy SlushySlushy SlushySlushy SlushySlushy


SlushySlushy SlushySlushy SlushySlushy SlushySlushy HardeniHardening slushng slush

SlushySlushy

Results: Trial 2 (continued)Results: Trial 2 (continued)

Cup #Cup # Amount Amount Of Salt Of Salt

85 mins.85 mins. 90 mins.90 mins. 95 mins.95 mins. 100 100 mins.mins.

#1#1 NoneNone -- -- -- --

#2#2 2mL2mL -- -- -- --

#3#3 4mL4mL -- -- -- --

#4#4 6mL6mL -- -- -- --

#5#5 8mL8mL -- -- -- --

#6#6 10mL10mL FrozenFrozen -- -- --

#7#7 12mL12mL SlushySlushy SlushySlushy SlushySlushy FrozenFrozen


FrozenFrozen -- -- --


of Saltof Salt10 10

mins.mins.20 20

mins.mins.30 mins. 30 mins. 35 35

mins.mins.40 mins.40 mins. 45 45

mins.mins.

#1#1 NoneNone NothingNothing Frost on Frost on CupCup

NothingNothing Starting Starting to Freezeto Freeze




#2#2 2mL2mL NothingNothing Frost on Frost on CupCup



In In process process of of FreezingFreezing





In In process process of of FreezingFreezing


NothingNothing NothingNothing Starting Starting to Freezeto Freeze












NothingNothing Frost on Frost on CupCup



Cup #Cup # Amount Amount of Saltof Salt

50 mins.50 mins. 55 mins.55 mins. 60 mins. 60 mins. 65 mins.65 mins. 70 mins.70 mins. 75 mins.75 mins.

#1#1 NoneNone In process In process of of

FreezingFreezing

NothingNothing FrozenFrozen -- -- --

#2#2 2mL2mL In process In process of of

FreezingFreezing



FreezingFreezing



FreezingFreezing

NothingNothing SlushySlushy NothingNothing SlushySlushy FrozenFrozen


FreezingFreezing

NothingNothing SlushySlushy NothingNothing SlushySlushy FrozenFrozen


FreezingFreezing

NothingNothing SlushySlushy NothingNothing SlushySlushy SlushySlushy

#7#7 12mL12mL NothingNothing NothingNothing SlushySlushy NothingNothing SlushySlushy SlushySlushy


In process In process of of

FreezingFreezing

NothingNothing SlushySlushy NothingNothing SlushySlushy SlushySlushy


Cup #Cup # 80 mins.80 mins. 85 mins.85 mins. 90 mins.90 mins.

#1#1 -- -- --

#2#2 -- -- --

#3#3 -- -- --

#4#4 -- -- --

#5#5 -- -- --

#6#6 FrozenFrozen -- --

#7#7 SlushySlushy Slush is Starting Slush is Starting to hardento harden

FrozenFrozen

#8#8 SlushySlushy Slush is starting Slush is starting to hardento harden

FrozenFrozen

Time for Samples to Time for Samples to FreezeFreeze

Trial Trial ##

#1-#1-NoneNone

#2-#2-2mL2mL

#3-#3-4mL4mL

#4-#4-6mL6mL

#5-#5-8mL8mL

#6-#6-10mL10mL

#7-#7-12mL12mL

#8-#8-Ocean Ocean WaterWater

# 1# 1 45 45 mins.mins.

45 45 mins.mins.

60 60 mins.mins.

75 75 mins.mins.

80 80 mins.mins.

85 85 mins.mins.

90 90 mins.mins.

85 85 mins.mins.

# 2# 2 45 45 mins.mins.

40 40 mins.mins.

60 60 mins.mins.

70 70 mins.mins.

75 75 mins.mins.

85 85 mins. mins.

100 100 mins.mins.

85 85 mins.mins.

# 3# 3 60 60 mins.mins.

55 55 mins.mins.

55 55 mins.mins.

75 75 mins.mins.

75 75 mins.mins.

80 80 mins.mins.

90 90 mins.mins.

90 90 mins.mins.

AnalysisAnalysisRate at which the Salt Water Mixtures

Froze

0

20

40

60

80

100

0 2 4 6 8 10 12 ow

Amount of Salt (mL)

Tim

e (

min

ute

s)

Trial 1Trial 2Trial 3

ConclusionConclusion

After gathering my information, it seems After gathering my information, it seems that in 200mL of ocean water, there is that in 200mL of ocean water, there is about 10-12mL of salt. My hypothesis was about 10-12mL of salt. My hypothesis was wrong. While I was doing my trials, I noticed wrong. While I was doing my trials, I noticed that the ocean water mostly froze at the that the ocean water mostly froze at the same time as the 10mL or the 12mL salt same time as the 10mL or the 12mL salt mixture. Therefore, I conclude that there is mixture. Therefore, I conclude that there is between 10 and 12mL of salt in 200mL of between 10 and 12mL of salt in 200mL of ocean water. To be more accurate I would ocean water. To be more accurate I would have to conduct more trials using 1mL have to conduct more trials using 1mL increments of salt.increments of salt.

Sources of ErrorSources of Error Where I placed the cups in the freezer was a big factor on Where I placed the cups in the freezer was a big factor on

how the mixtures froze, because it was colder in the back how the mixtures froze, because it was colder in the back of the freezer rather than the front (I learned this the hard of the freezer rather than the front (I learned this the hard way and had to redo the whole trial)way and had to redo the whole trial)

It was tricky to measure the salt and the water, so it It was tricky to measure the salt and the water, so it might not be exactly right.might not be exactly right.

How warm or cold the mixtures are. (I left the mixtures on How warm or cold the mixtures are. (I left the mixtures on the counter for 24 hours before doing my experiments)the counter for 24 hours before doing my experiments)

Any chemicals in the tap water could have affected the Any chemicals in the tap water could have affected the results in freezing.results in freezing.

The temperature of the freezer each time I used it.The temperature of the freezer each time I used it. If the salt was not completely dissolved and stirred If the salt was not completely dissolved and stirred

throughout, there may have been surface freezing of throughout, there may have been surface freezing of plain water.plain water.

Amount of time the freezer door was open while I Amount of time the freezer door was open while I collected my data.collected my data.

Ways to ImproveWays to Improve

1.1. Try the experiment again, except Try the experiment again, except this time instead of going up in this time instead of going up in increments of 2mL, for the amounts increments of 2mL, for the amounts of salt, go up by 1mL each time.of salt, go up by 1mL each time.

2.2. Try boiling amounts of ocean water Try boiling amounts of ocean water and collecting the residue of salt. and collecting the residue of salt. Measure the amount of salt Measure the amount of salt remaining.remaining.

3.3. Try using rock salt instead of table Try using rock salt instead of table salt. salt.

Documents

How Much Salt is in Ocean Water?. Purpose To determine how many mL of salt there is in 200mL of ocean water. To determine how many mL of salt there is