C8 - Chemical Analysis Flashcards
A chemically pure substance will…
- Melt at a specific temperature
- Boil at a specific temperature
What are formulations and what are 3 examples?
Formulations are useful mixtures with a precise purpose.
1. Medicines
2. Fertilisers
3. Fuels
What is the test for hydrogen?
Squeaky pop test.
Hydrogen gas in an open test tube with a lightened splint and burns quickly with a pop.
What is the test for oxygen?
Oxygen gas in an open test tube and glowing splint will be relit.
What is the the test for chlorine?
Chlorine gas in a test tube and will bleach damp litmus paper white.
What is the test for carbon dioxide?
Limewater in a test tube. Makes limewater turn cloudy when shaken or bubbles thought it with co2.
What is an anion?
An ion with a negative charge
What is a cation?
An ion with a positive charge.
What is the test for carbonates?
Add a couple of drops of dilute acid.
Connect the test tube to a test tube of limewater.
Carbonate ions react to form carbon dioxide, which will turn the limewater cloudy.
What colour flame will lithium ions go?
Crimson flame
What colour flame will sodium ions go?
Yellow flame
What colour flame will potassium ions go?
Lilac flame
What colour flame will calcium ions go?
Orange - red flame
What colour flame will copper ions go?
Green flame
What is a disadvantage of the flame test for testing metal cations?
If the sample contains a mixture of metal ions, the flame colours of some ions may be hidden by the colours of others.
What are three advantages of using instrumental analysis ( using machines to analyse unknown substances)?
- Sensitive - can detect even the tiniest amounts
- Fast - tests can be automated
- Accurate
