Practicals (lab book) Flashcards
what is the method for determining the formula of a hydrated salt?
Step 1- weigh an empty crucible
Step 2- Add 2 g hydrated salt to the crucible and reweigh
Step 3- Place crucible on pipe clay triange and heat gently for 1 minute then strongly for 5
Step 4- Leave to cool for 5 minutes then reweigh
step 6- heat strongly for 1 minute leave to cool and reweigh
step 7- repeat until mass remains constant
Step 8- calculate moles
What is the method for determining the RAM of a mental by experiemnt?
1-set up apparatus
2- Using a measuring cylinder add 50cm3 of distilled water to the conical flask
3- Weigh out your sample of group 1 metal. Record the exact mass.
4- Remove the stopper add magnesium to the flask and quickly replace the stopper
5- Collect gas and record final volume of hydrogen
Method for determination of concentration of HCl part 1
1- using a weighing boat weigh 2.10g solid sodium hydrogencarbonate. Transfer to 100cm3 beaker. Rise weighing boat with distilled water into beaker.
2- Add enough distilled water to dissolve solid stiring with a glass rod
3- Transfer to 250cm3 volumetric flask. Rise out funnel beaker and glass rod with distilled water into flask
4- make up to just below the mark with distilled water insert stopper and slowly invert to mix
Concentration of HCl part 2
Step 1-Transfer to a beaker
Step 2- Use a pipette and filler to transfer 25cm3 to 250 cm3 conical flask
Step 3- Add a few drops of methyl orange to the flask
Step 4- Rise burette with hlc then fill
Step 5- Titrate with constant swirling until end point (yellow to orange) is reached. This is trail.
Step 6- repeat experiment until concordant results are obtained
Step 7- ensure all findings are acurate to the nearest 0.05cm3
Identification of an unknown carbonate equation and method
X2CO3 (aq) + 2HCl - 2XCl (aq) + H2O (l) + CO2 (g)
Step 1- weigh bottle provided
Step 2- Tip into 250cm3 beaker and reweigh
Step 3- Dissolve in distilled water stiring constantly
Step 4- Transfer to 250cm3 volumetric flask. Rinse all equipment with distilled water
Step 5- Make up to just below the mark with distilled water insert stopper and invert to mix
Step 6- Transfer 25cm3 to conical flask
Step 7- Add 3-4 drops methyl orange
Step 8- rise and fill burette with 0.1 mol HCl
Step 9- Titrate with constant swirling until end point is reached
Step 10- Repeat until concordant results are obtained
Molar mass of an acid part 1
H3X + 3NaOH - Na3X + 3H2O
Step 1- Weigh bottle provided
Step 2- tip into 250cm3 beaker and reweigh the bottle
Step 3- Dissolve in distilled water stiring with a glass rod
Step 4- Transfer to volumetric flask. Rinse equipment with distilled water into flask
Step 5- Make up just below the mark with distilled water and mix
Molar mass of an acid part 2
Step 6- Using a pipette and filler transfer 25cm3 sodiuum hydroxide solution to conical flask
Step 7- Add 3-4 drops phenophaline indicator
Step 8- Rise and fill burette with solution from volumetric flask
Step 9- Titrate sodium hydroxide with unknown hydrated acid until end point is reached pink to faint pink
Step 10- repeat until concordant results are obtained
Outline the method for testing for Halides
Make a solution of the halide
Acidify with dilute nitric acid
Add a few drops of silver nitrate solution
Treat any precipitate with dilute ammonia solution
If precippitate remains add concentrated ammonia solution
What observations will be made when Silver chloride iodide and bromide are present?
Chloride- white precipitate
Bromide- cream precipitate
Iodide- yellow precipitate
Method for reaction of oxides with water
Place a small quantity of magnesium oxide and calcium oxide into two seperate test tubes
Add 10cm3 deionised water to each tube, shake well and record observations
Add 3 drops of universal indicator to each tube, gently shake and record PH
Method for Thermal stability of group 2 carbonates
Place about 1 cm depth of each of the anhydrous group 2 carbonates into four seperate boiling tubes
Set up appropriate apparatus
Strongly heat boiling tube containing carbonate for several minutes
Note how rapidly the gas is evolved and the extent to which the limewater becomes milky. Remove tube from limewater as soon as heating is stopped
Method for identifying group 2 salts part 1
Transfer 25cm3 disilled water to a beaker
Tip mixture A into the water and stir with a glass rod
Filter the mixture into a conical flask
Add about 1cm depth of the filtrate to a test tube
Add five drops of HNO3 followed by ten drops of AgNO3. Record observations.
Add NH3 dropwise to the test tube until no further change occurs
Add a spatula measure of residue from step 3 to a test tube
Keep adding HNO3 until no further change occurs
Identifying group 2 salts part 2
Add filtrate from step 3 to a new test tube
Add roughly the same volume of H2SO4. Record observations
Add filtrate from step 3 to a new test tube
Add roughly the same volume of K2CrO4. Record observations.
Method for identifying unknowns
Plan and carry out a series of tests that would allow you to identify solutions A-D
Carry out minimum amount of tests required. Each should produce a positive result.
Record tests you have carried out
Record all observations
Identifying the unknowns using only the unknowns
Plan and carry out a series of tests that would allow you to identify each solution A-E
Carry out the minimum number of tests required. Each one should produce a positive result.
Record all tests
Record all observations
