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      <title>3A-seashell planning experiment by nabilah</title>
      <link>https://padlet.com/nabilah_/3Aplanningseashell</link>
      <description>Determine which seashell has the higher percentage of calcium carbonate. </description>
      <language>en-us</language>
      <pubDate>2017-03-28 05:25:55 UTC</pubDate>
      <lastBuildDate>2025-09-27 22:58:14 UTC</lastBuildDate>
      <webMaster>hello@padlet.com</webMaster>
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         <title>Mass of seashell</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028340</link>
         <description><![CDATA[<div>Renish and Jonavan<br>Procedures:<br>1. Measure the mass of seashells in a beaker using the electronic balance. Take 10g of each seashell sample.<br>2.Add excess HCl into the seashell sample X in the first conical flask and measure the total mass to check how much HCl has been used. Upon adding the excess HCl, cover the mouth of the conical flask with a stopper to prevent CO2 from escaping.<br>3. Measure the mass of HCl that you are going to use in another beaker and add it into the conical flask containing the sample of seashell Y.<br>4. Upon <br>Constant variables:<br>-Type of acid used<br>-Mass of acid used<br>-Mass of seashell sample used<br>Changed variables:<br>-Type of seashell (percentage of CaCO3)<br>Dependent variable:<br>-Change in mass<br>Apparatus needed:<br>-2 Beakers<br>-Electronic balance<br><br></div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:27:09 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028340</guid>
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         <title>Determine the shell with the highest percentage of Calcium Carbonate. Athuf &amp; Cheyanne</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028420</link>
         <description><![CDATA[<div>approach: mass loss method<br>variables: <br>-KepConstant: vol of acid used and mass of shell used<br>-Change: percentage of calcium carbonate in each shell<br><br><br>1. Measure 500ml of hydrochloric acid using a measuring cylinder and  pour it into two beakers with 250 ml in each.<br>2. Weigh the mass of the shells using an electronic balance and ensure that both shells X and Y are 5g each.<br>3. Put shell X in one beaker and shell Y in another and allow the shells to fully react with the acid which can be seen when shells X and Y stop decreasing in size.<br>4. When the reaction is completed, remove both shells from their beakers and dry them with a cloth.<br>5. Measure the new mass of each shell using an electronic balance.<br>6. Calculate the mass lost for each of the shells by taking the initial mass - new mass.<br>7. Repeat the experiment several times and collate the results in a table. Then compare which shell type, X or Y, loses more mass.<br>8. The shell that loses the most mass has the higher percentage of Calcium Carbonate.</div>]]></description>
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         <pubDate>2017-03-28 07:27:31 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028420</guid>
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      <item>
         <title>SEASHELL PLANNING EXPERIMENT</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028481</link>
         <description><![CDATA[<div>Faiz &amp; Ariel<br>steps: <br>1. Put 5g of shell X and 5g of shell Y into 2 separate conical flasks.<br>2. Add an equa<del>l amount</del>  <strong>VOLUME </strong>of <strong>excess</strong> H2SO4 into both conical flasks. <br>3. Stopper the reaction and<del> collect  </del><strong>measure </strong>the CO2 gas in gas syringe.<br>4. Record volume of CO2 collected for both reactions.<br>5. Record in a table<br>6. Repeat steps 1 to 4 and find the average of both volumes of CO2 collected for each flask.<br>7. The reaction which produces more CO2 has a higher percentage of CaCO3</div>]]></description>
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         <pubDate>2017-03-28 07:27:45 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028481</guid>
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      <item>
         <title>Mass Loss Method</title>
         <author>Sapphirestarz</author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028484</link>
         <description><![CDATA[<div>timothy and jiayi<br><br>Required apparatus :<br>2 Beakers<br>Seashells<br>Acid<br>Timer<br>Electronic balance<br>Filter funnel, filter paper<br><br>Variable to change : Shell used<br>Variable to keep constant : <br>Type of beaker<br>Time of experiment<br>Type of seashell used<br>Type of acid<br>Variable to measure : Initial seashell mass, mass of residue at end of experiment<br>Data to process : Mass lost by seashell<br><br>1. Weigh initial seashell X with an electronic balance and record in table.<br>2. Add excess hydrochloric acid to a beaker containing the seashell and time for 30 minutes   <strong>(cannot assume reaction has ended)</strong><br>3. After 30 minutes, filter the mixture using filter paper and dry the residue.<br>4. Weigh residue on electronic balance and record value.<br>5. Calculate the difference by taking the value of Step 1 and deducting the value from step 4. Record final value.<br>6. Repeat step 1 to 5 with Seashell Y.</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:27:45 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028484</guid>
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         <title>Pei Yee &amp; Bryan</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028485</link>
         <description><![CDATA[<div>Constant Variables: 1) initial mass of the seashells<br>2) the volume of acid used in both reactions<br>3) type of flasks used<br><br>Independent variable: the seashell used<br><br>Dependent variable: the final mass of the seashell<br><br><br>Steps:<br><br>1) Weigh the mass of the two seashells using an electronic balance, and record the masses as M1 and M2<br><br>2) Add 100 ml of hydrochloric acid in <strong>excess</strong> to both seashells in separate conical flasks<br><br>3)wait for the reaction to stop which is when there is no more effervescence<br><br>4) filter the mixture using a filtration funnel to obtain the <strong>residue </strong>seashell and dry the residue using filter paper<br><br>5) weigh the final mass of the seashells and record it as FM1 and FM2<br><br>6) calculate the percentage mass change by subtraction the intial mass from the final mass, divide it by the initial mass and multiply it by 100%, e.g. FM1 - M1 /M1 x 100%<br><br>7) compare the percentage change <br><br><br></div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:27:46 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028485</guid>
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      <item>
         <title>Determining the percentage of CaCO3 ( in seashells</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028490</link>
         <description><![CDATA[<div>Joel and Serene<br><br>APPROACH<br>Add HCl (aq) to each shell and collect and measure volume of gas produce with gas syringe.<br><br>VARIABLES<br>Changed: <br>- Shell used<br>Constant:  <br>- Volume of HCl (aq) used<br>- Surrounding temperature<br>- Container used<br>Measured: <br>- Volume of CO2 (g) produced<br><br>PROCEDURE<br>1. Add excess HCl (aq) of the same volume to each conical flask labeled X and Y.<br><br>2. Drop Shell X into flask X and Shell Y into flask Y.<br><br>3. Attach delivery tube with gas syringe onto each flask as soon as the shell is added and collect CO2 (g) produced.<br><br>4. <strong>When effervescence stops</strong>, measure the volume of CO2 (g) in each gas syringe.<br><br>COLLECTING DATA<br>Record the volume of CO2 (g) produced by Shell X as V1 and Y as V2.<br><br>PROCESSING DATA<br>Compare the value of V1 and V2. The higher value of CO2 (g) produced in the setup has the shell with the higher percentage of CaCO3 (s).</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:27:46 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028490</guid>
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      <item>
         <title>Mass Of Seashell - Kai Sheng Chhavi</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028549</link>
         <description><![CDATA[<div>Variables changed: Type of shell<br>Variables constant: Amount of HCl <br>What we measure: Difference in initial mass of seashell and final mass of seashell<br><br>Approach:<br>1) Measure initial mass of both seashell X and Y<br>2) Place both shells into 2 separate beakers<br>3) Add excess amount of HCl into both beakers<br>4) Allow the reaction to be completed<br>5) When effervescence and decrease in size of the seashell stops, the reaction has stopped<br>6)Remove the shells from the acid and dry them with a cloth<br>7) Measure the mass of the shells at the end<br>8) Calculate the difference in mass from the start<br>9) The shell with the higher change in mass has a higher CaCO3 percentage<br><br>Apparatus:<br>1 Electronic Balance<br>2 Beakers<br>Cloth (For drying)<br><br>Materials:<br>2 Different shells (X and Y)<br>Hydrochloric acid<br><br>Quantities<br>Mass of shell at start and end<br><br>Data Processing<br>Initial mass - Final mass = Difference in mass</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:28:02 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028549</guid>
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      <item>
         <title>Nic and Vic</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028550</link>
         <description><![CDATA[<div>Changed Variable:<br>Mussel shall.<br><br>Measured:<br>Mass of shell before and after experiment(Mass difference)<br><br>Constant Variables:<br>Type of Acid Used.<br>Volume of acid used.<br><br>Procedure:<br>1)Weigh Shell X using an electronic balance and label it w1.<br>2) Measure 100cm^3 of sulfuric acid using a measuring cylinder and pour it into a beaker.<br>3) Add Shell X to the beaker and wait for the reaction to be complete(when effervescence stops)<br>4)Weigh shell X again with the electronic balance and label it w2.<br>5)Calculate percentage change in mass of Shell X using the formula ((w2-w1)/w1)*100% to obtain the percentage of CaCO3 present in the shell.<br>6) Repeat Steps 1-5 using Shell Y.<br>7) Compare the 2 percentages and determine which shell has a higher percentage of Calcium Carbonate.<br><br></div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:28:03 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028550</guid>
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         <title>Mass of residue test - Josh &amp; Soey Yin</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028691</link>
         <description><![CDATA[<div>Approach: <br>1. add excess HCl to both seashells<br>2. measure mass of residue obtained when effervescence has ceased<br><br>Variables:<br>-changed variables<br>&nbsp; &nbsp;&gt;type of shell (X, Y)<br>-constant variables<br>&nbsp; &gt;volume of HCl acid added to both seashells<br>&nbsp; &gt;initial mass of seashells<br>&nbsp; &gt;size/contact surface area of seashells with acid<br>-measured variables<br>&nbsp; &gt;mass of residue obtained.<br><br>Apparatus needed:<br>-electronic balance<br>-measuring cylinder<br>-3 pieces of filter paper<br>-filter funnel<br>-conical flask<br><br>Steps:<br>1.measure mass of seashell X using <strong>electronic balance</strong> (m1)<br>2. add 100cm3 of excess HCl acid to seashells. use <strong>measuring cylinder</strong> to obtain 100cm3 of HCl first.<br>3. After effervescence has stopped, filter mixture using filter paper and filter funnel to<strong> obtain residue</strong>.<br>4. Dab residue dry with 2 pieces of filter paper.<br>5. measure mass of residue using electronic balance. (m2)<br>6. repeat steps 1 to 6 using seashell Y<br>Data Processing:<br>6. Calculate percentage of CaCO3 in seashell X and Y by taking (m1-m2)/m1 x 100%</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:28:40 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028691</guid>
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         <title>Change in mass - Darren &amp; Wenxin</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028714</link>
         <description><![CDATA[<div>What are the essential apparatus?<br>-2 conical flasks<br>-2 different types of mussel shell, X and Y<br>-Electronic beam balance<br>-Dilute hydrochloric acid<br><br>Approach?<br>-Add mussel shells in different conical flasks and measure the change in mass of the contents (mussel shells &amp; HCl)<br><br>Changed variables: Type of mussel shell<br><br>Constant variables: <br>-environment (e.g. wind)<br>-initial mass of shell<br>-volume of HCl acid<br><br>Measured variable: changed in mass of the mussel shells<br><br>1. Record the initial mass of both shells<br>2. Measure the final mass of both shells after the acid is added to the mussel shells. (Ensure that the acid reaction had completed)<br>3. Calculate the change in percentage of mussel shells by taking the initial mass of the mussel shells and subtract it by the final mass. Then, multiply it by 100%. (processed data)<br><br></div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:28:47 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028714</guid>
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         <title>Jannaa &amp; Steveee</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028767</link>
         <description><![CDATA[<div>Approach: <br>React the shells with excess hydrochloric acid and calculate the percentage change in mass of both seashells.<br><br>Variables: <br>Independent- The type of shell<br>Constant- Type &amp; volume of acid, mass of beaker.<br><br>Apparatus: <br>-Electronic balance<br>-Beakers<br>-Measuring cylinder<br><br>Steps:<br>1.Wash and dry the seashells<br>2.Place the shells into two seperate beakers.<br>3.Measure and record the intial mass of the shell in the beakers using an electronic balance.<br>4.Add excess hydrochloric acid into both of the seashell samples using a measuring cylinder.<br>5.Wait for the reaction to end by the absence of effervescence.<br>6.Filter the mixture and collect the residue of seashell samples.<br>7.Measure the mass of the residue separately using an electronic balance.<br>8.Repeat steps 3-7 and find the average mass for both seashells<br>9.Record the final mass and calculate the percentage change in mass of both seashells.</div>]]></description>
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         <pubDate>2017-03-28 07:29:04 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028767</guid>
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         <title>Eileen and ben</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028791</link>
         <description><![CDATA[<div>Gas syringe method.<br>Variables:<br>Constant: Initial mass of seashells, concentration of acid.<br>Independant: Type of seashell used<br>Dependant: Amount of CO2 collected.<br>Steps:<br>1) Place seashell A into a conical flask filled with excess hydrochloric acid.<br>2) Immediately connect conical flask to a gas syringe using a delivery tube.<br>3) Wait until no more bubbles are formed, indicating that all the calcium carbonate in the shell have reacted with the acid.<br>4) Measure and record amount of CO2 produced by reaction.<br>5) Repeat Steps 1-4 with seashell B<br>6) Compare amount of CO2 produced in both reactions. The reaction with the seashell that produced more CO2 contains a higher percentage of calcium carbonate and thus have a higher quality.</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:29:09 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028791</guid>
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      <item>
         <title>Caleb-Gas syringe method</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028821</link>
         <description><![CDATA[<div>constant variables: <br>1. Type of acid<br>2. Volume of acid used<br>3.Mass of seashell<br>Changed variables:<br>1.Seashell<br><br>Procedure: <br>1.Place seashell X in a<del> test tube   </del><strong>beaker/conical flask</strong><br>2.Add <strong>excess</strong> HCl into the test tube containing the seashell X<br>3.Collect the <del>amount</del> of CO2 gas produced from the reaction using the gas syringe method <del>via the downward delivery method</del><br>4.Place seashell Y into a test tube<br>5.Repeat steps 1 to 3 while ensuring that the amount of HCl used is the same amount as the first time round<br>6. Compare the amount of CO2 gas collected from both the experiments. The experiment that has collected more CO2 gas is the seashell that has a higher percentage of calcium carbonate.<br><br>Apparatus to be used:<br>1.Gas syringe<br>2.Delivery tube<br>3.Test tubes<br><br>Quantity to be measured:<br>The amount of CO2 gas collected from the reaction of seashell and HCl acid</div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:29:20 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028821</guid>
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         <title>Haixin and Javienne</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028837</link>
         <description><![CDATA[<div>method: percentage change in mass approach: add excess hydrochloric acid to the seashells and measure the percentage changed in mass using an electronic balance.<br><br>variables to be changed: the types of shell<br><br>variables to be kept constant: the amount of HCl added to the seashell and the temperature and relative humidity of the surrounding.<br><br>apparatus: 2 beakers, electronic balance, 2 conical flasks, 2 filter funnels and 2 pieces ofbfilter paper.<br><br>steps: <br>1. measure the initial mass of shell x and record it as m1. measure the mass of shell y and record it as m2.<br>2. add excess hydrochloric acid to shell x in a beaker and wait for the reaction to be completely finished.<br>3. filter the mixture and collect the residue and leave it to dry. <br>4. measure the mass of the residue and record it as m3.<br>5. calculate the percentage changed in mass for shell x using (m1-m3/m1) x 100%.<br>6. repeat steps 2-5 using shell y and compare the percentage changed in mass of the 2 shells.<br><br></div>]]></description>
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         <pubDate>2017-03-28 07:29:23 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028837</guid>
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         <title>Ali 💣and cewlett👲 </title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028985</link>
         <description><![CDATA[<div>Determining the percentage of CaCO3 in mussels.<br>1.Measure the initial mass of each mussel separately using an electronic balance (m1)<br>2.place both mussels into 2 small conical flasks separately<br>3.Measure the same volume of hydrochloric acid using a measuring cylinder for both flasks<br>4. Pour the same volume of  hydrochloric acid in excess into each flask<br>5. Wait for all the calcium carbonate to react with the acid by observing if effervescence stops.<br>6..After reaction is completed remove and dry the mussels with filter paper<br>7.Measure final mass of mussels using electronic balance(m2)<br>8.Use formula to determine percentage change mas  M!-M2/M1 x 100<br><br></div>]]></description>
         <enclosure url="" />
         <pubDate>2017-03-28 07:30:00 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163028985</guid>
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         <title>Bussa and Celestine</title>
         <author></author>
         <link>https://padlet.com/nabilah_/3Aplanningseashell/wish/163029109</link>
         <description><![CDATA[<div>MASS LOSS METHOD<br>Variables :<br>Kept constant:<br>-Mass if shell<br>-Volume of HCl<br><br>Independent: <br>Type of shell<br><br>Dependent:<br>Change in mass<br><br>Apparatus<br>- Balance<br>- 3 Beaker<br>- Measuring cylinder<br><br>Quantity to be measured:<br>Change in mass of the contents of the beaker<br><br>Data collected:<br>Loss in mass in grams using a electronic balance. <br><br>Data process:<br>Calculate percentage of calcium carbonate in shell.<br><br><br>Steps:<br>1. Place beaker on the balance measure its mass.<br>2. Pour 60cm3 of HCl into the beaker, measure using measuring cylinder.<br>3. Weigh 5grams of Sample X using another balance.<br>4. Place Sample X in HCl, and record initial mass of beaker+contents. <br>5. Wait till there is no change in mass, and no more effervescence is produced<br>5.Record final mass. And calulate change in Mass. (Final-Initial)<br>6.Repeat steps 2-5 with sample Y.<br>7.The sample with more loss of mass is the Sample with a higher percentage of Calcium carbonate.</div>]]></description>
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         <pubDate>2017-03-28 07:30:36 UTC</pubDate>
         <guid>https://padlet.com/nabilah_/3Aplanningseashell/wish/163029109</guid>
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