Atoms & The Periodic Table / Name:
Pre-Lab Questions:
1. When observing a reaction occurring in a test tube, what tells you that a gas is being formed? How would you compare two reaction tubes to determine the one in which the reaction is happening more rapidly?
2. What factors affect the reactivity of metals?
3. What colour is phenolphthalein in acid solutions? In basic solutions?
4. What is the WHMIS symbol for acids? Describe the precautions you would nee to take when working with acids?
MARK SCHEME / POSSIBLE MARKS / MARKS OBTAINEDTITLE / Clearly stated / 1
PURPOSE / Clearly stated / 2
METHOD / Sheet attached / 1
RESULTS / Detailed and organised in table form to show all results for each Part / 24
DISCUSSION / Group 1 and 2 elements and compounds compared
2 Errors discussed
Real-life application provided / 12
4
1
CONCLUSIONS / Brief conclusions about Group 1 and 2 elements / 6
SAFETY / Work safely at all times
Keep work space clean and organised / 5
TOTAL / 55
METHOD
1. GROUP I ELEMENTS
Observe the demonstration of the reactions of Group I elements. Make notes on the appearance of these elements and their reaction with water.
2. GROUP II ELEMENTS
Examine the group II metals provided and record your observations.
Burn a piece of magnesium in a Bunsen flame. Place the residue on a white tile and record observations. Add some water to the residue and add one drop of Universal indicator. Note the pH.
Place a small piece of calcium metal on a gauze mat on a tripod. Carefully direct a hot Bunsen flame on to it. Observe and record results. Add the residue to water and add one drop of Universal indicator. Note the pH.
Add a piece of magnesium to water in a test tube to which a few drops of phenolphthalein have been added. Leave for 15 minutes and record observations. Then heat the mixture and observe any changes.
Add a small piece of calcium to cold water and phenolphthalein in a test tube. Record observations.
In separate test tube react magnesium and calcium with dilute hydrochloric acid and record observations.
3. COMPOUNDS OF GROUP I ELEMENTS
(A) Observe each of the group I salts available and record their name, appearance and colour. A sample of each of the hydroxides will be left on a white tile on the front bench. Note the changes that occur to these salts when left exposed to the air.
(B) Determine the solubility of each salt in water by adding 1 r.g. to 2cm3 of water. Make note of any changes that occur when the sample is added to water. Add 2 drops of Universal indicator to each and determine the pH of each solution.
4. COMPOUNDS OF GROUP II ELEMENTS
(A) Observe each of the group II salts available and record their name, appearance and colour.
(B) Determine the solubility of each salt in water by adding 1 r.g. to 2cm3 of water. Make note of any changes that occur when the sample is added to water. Add 2 drops of Universal indicator to each and determine the pH of each solution. Record your results.
DISCUSSION
Compare the Group 1 elements with each other, the Group 2 elements with each other and then the Group 1 elements with the Group 2 elements. In each case consider their appearance, properties and reactivity with oxygen and water. Look for similarities and differences.
Repeat for the compounds.
Discuss two different errors that may have impacted on your observations.
Provide one real-life application for the reactivity of Group I metals.
CONCLUSIONS
What can you conclude about the nature of the elements in Groups I and II?