1. Cleaning Glassware Apparatus SMK Negeri 13 Bandung

2. Teknologi dan Rekayasa Objectives After this session, the students are expected to be able : 1.To identify types of glassware 2.To identify types of impurities 3.To identify types of cleaner and how to make them

3. Teknologi dan Rekayasa Common Types of Volumetric Glassware  Flasks  Pipettes  Burettes

4. Teknologi dan Rekayasa Common Types of Volumetric Glassware  Flasks  Volumetric flask is a flat- bottomed pear-shaped vessel with a narrow neck.  A thin line etched around the neck indicates (usually) a certain volume of liquid that is held at some definite temperature.  Volumetric flask are used for preparing solutions of known concentration.

5. Teknologi dan Rekayasa Common Types of Volumetric Glassware  Pipettes  Common pipettes are cylinders drawn out at each into narrow open tubes.  A pipette use to measure out one definite volume of liquid is known as a transfer pipette.  Measuring pipettes are narrow tubes subdivided into many divisions, which are employed for measuring out variable amounts of liquid. Measuring pipette Transfer Pipette

6. Teknologi dan Rekayasa Common Types of Volumetric Glassware  Burettes  Burettes are long, graduated tubes of uniform bore provided with a stopcock.  Used for delivering variable amounts of liquid and are therefore subdivided into many small divisions.  Used principally in titration.

7. Teknologi dan Rekayasa Cleaning Volumetric Glass  Glassware must be perfectly clean and free from grease, otherwise the result will be unreliable.  One test for cleanliness of glass apparatus is that on being filled with distilled water and the water withdrawn, only an unbroken film of water remains. If the water collect in drops, the vessel is dirty and must be cleaned.

8. Teknologi dan Rekayasa Types of Impurities  Grease  Rusty  Fungi  Residue  Carbon  Ink spot

9. Teknologi dan Rekayasa Types of Cleaner  Sodium or potassium dichromate in concentrated sulfuric acid  Alcoholic KOH  Teepol

10. Teknologi dan Rekayasa Sodium or Potassium dichromate in Concentrated Sulfuric Acid  Solute 70 gram sodium or potassium dichromate (Na 2 Cr 2 O 7.2H 2 O or K 2 Cr 2 O 7.2H 2 O) in 100 mL of water, then add 900 mL of concentrated H 2 SO 4.  Filling the apparatus with sodium or potassium dichromate in concentrated sulfuric acid, and allowing it to stand for several hours, preferably overnight. Then poured off the acid, rinsed the apparatus with distilled water, and allowed to drain until dry.

11. Teknologi dan Rekayasa Alcoholic KOH  Dilute 100 gram KOH in 100 mL of distilled water, then add 900 mL alcohol 95 %.  Rinse the apparatus with alcoholic KOH for 5 minutes, then rinse with detergent and water.

12. Teknologi dan Rekayasa Teepol  Dilute 10 mL teepol in distilled water add until 100 mL.  Rinse the apparatus with alcoholic KOH for 5 minutes, then rinse with detergent and water.