required practicals

Question 1

What is practical for chromatography?

Answer 1

• Put paper with two different inks on them in a solvent (water), place a lid on the container to stop evaporating.
• Different inks will move up the paper at different rates.

Question 2

How would you test reactivity in group 1 alkali metals?

Answer 2

• Drop a small amount of lithium into cold water (the reaction should be slow with some fizzing.)
• Do the same with sodium and potassium.
• Potassium should be the most reactive.

Question 3

How would you test for metal/positive ions?

Answer 3

• Soak wooden splint in the test compound then hold in bunsen burner and see the colour change.

Question 4

How would you test for carbonates?

Answer 4

• Add HCL to the compound being tested and place a bung on top with the delivery tube into limewater.
• If a carbonate is present the limewater will turn from clear to cloudy.

Question 5

How would you test for halide ions?

Answer 5

• Add nitric acid and silver nitrate.
• Chloride will go white.
• Bromide will go cream.
• Iodide will go yellow.

Question 6

How would you investigate solubility?

Answer 6

• Add a known mass of solute to 100ml of water and filter it. Weigh the undissolved solute and deduct that from the original mass. Repeat with different temperetures.

Question 7

How to you test for hard and soft water?

Answer 7

• Add 1cm cubed of soap to your water and shake, repeat this until your bubbles last over 30 seconds.
• The less soap needed, the softer the water.