concentrate!

Task 1:

Make a standard solution:

• Place the watch glass on the balance, making sure that it is set at zero. Then carefully weigh the amount of substance needed
• Next transfer the measured amount of the substance in a beaker. From here add water to dissolve it.
•  With the glass rod stir the the solution until all the solid is dissolved, next pour the solution into the volumetric flask.
• Now, water must be added just below the line on the volumetric flask. Making sure the meniscus is on the line, this can be done by adding a few drops with a teat pipette.
• Following this, you should place the lid of the volumetric flask on and shake the flask a couple times to mix the the solution.
• The number moles needed required for the solution.
• Work out the required volume and concentration needed ( m= C times V ). Measurements for Concentration is dm^3 and Volume would be dm3.
• To be able to find the required measurement. you will need to divide the volume by 1000 to get it in dm3.
• From here you should find the RFM ( relative formula mass) of the chosen substance.

Once all the measurements are done and accurate, move on to task two.

Task 2:

• Place the balance on a nice and even surface ( making sure its calibrated & set at zero)
• Place the watch glass on the balance and measure the mass of solution needed.
• Pour the hydrochloric acid into the burette, leaving the tap open with a beaker under the tap ( You can use a small funnel to make it easier )
• Stop when the burette is full. Once it is full close the tap, from here add more of the solution up to the zero mark
• Using the pipette to transfer the sodium hydroxide solution to the volumetric flask. Once this is completed two drops of the phenolphthalein indicator should be added
• With the glass rod mix the solution gently.
• Place the volumetric  flask on piece of clean white paper under the burette tap.
• From here hydrochloric acid should be added to the sodium hydroxide solution very slowly, mix gently after each time the hydrochloric acid is added.
• Continue until solution goes a clear colour
• The coloured solution should then be rinsed down the sink.
• The HCL should be added drop by drop into the NaOH until the solution goes from pink to colorless, from this point no more HCL should be added and the solution should be recorded.

Task 3:

• Convert the 100 ml to dm^3 – 0.1dm^3  ( 100/1000 )
• 0.5/0.1 = 0.2 using the formula m = C times V
• Hydrochloric acid + sodium hydroxide → sodium chloride + water
• HCL + NaOH —-> NaCl + H2O

Equipment:

• Watch glass
• Balance
• Beaker
• Wash bottle
• Glass rod
• Volumetric flask
• Teat pipette
• Pen
• Lables
• Goggles
• Burette
• HCL
• NaOH (solid)
• Phenolphthalein

http://www.creative-chemistry.org.uk/alevel/module1/documents/N-ch1-49.pdf

Risk Assessment:

Sodium hydroxide Can cause chemical burns on the skin – therefore do not touch solution with your hands, wear gloves for extra protection and wash your hands immediately if the solution get on your hands.

NaOH is a Caustic solution, you should proceed with great care when handling.

Add water to NAOH slowly, this is to prevent the sodium hydroxide pellets from reacting to violently.

Always stay standing, so that in case of spillage of the solution you can move out of the way.

Wear goggles  when doing the experiment this is to protect your eyes.

Glass wear from the beaker or volumetric flask and burette are breakable. This can cause stabbing or cutting the hand. Be careful when handling

The balance can cause an electric shock, so do not place near water and make sure your hands aren’t wet when handling