Test for ions Flashcards
How do you test for hydrogen?
Put a lit splint into a test tube and you will hear a squeaky pop if hydrogen is present
How do you test for oxygen?
Put a glowing splint into a test tube the match well relight if oxygen is present
How do you test for carbon dioxide?
Bubble the gas (co2) into lime water and it will change form colourless to milky if co2 is present
How do you test for ammonia?
Put damp red litmus paper into the mouth of a test tube the litmus paper will turn blue if ammonia is present
How do you test for chlorine?
Damp blue litmus paper into the mouth of a test tube it will turn white if chlorine is present
What are cations?
Positive ions
What are anions?
Negative ions
What are the 3 test for cations? (3)
- Flame tests
- Ammonium test
- Copper (ll), iron (ll), iron (lll)
What are the 3 test for anions?
- Chloride, bromide, idide
- Sulphate
- Carbonate
What is the test for water?
Use anhydrous, it will turn from white to blue if water is present
What are the 5 ions used in the flame tests and there chemical symbol? (5)
- Lithium Li^+
- Sodium Na^+
- Potassium K^+
- Calcium Ca^2+
- Copper Cu^2+
How do you carry out a flame test? (3)
- Dip wire loop into HCl
- Then into a solid compound
- Place it under the bunsen flame
What is important to keep in mind when carrying out a flame test?
To clean the wire loop each time by dipping it into the HCl
What is the positive result for lithium in a flame test?
Crimson
What is the positive result for sodium in a flame test?
Yellow
What is the positive result for potassium in a flame test?
Lilac
What is the positive result for calcium in a flame test?
Brick red
What is the positive result for copper in a flame test?
Green
How do you carry out the ammonium test? (2)
- Add sodium hydroxide and warm
- Test the gas produced with damp litmus paper
How do you carry out the test testing for copper (ll), iron (ll), iron (lll)?
- Add sodium hydroxide
What is the positive result for the ammonium test?
Blue/purple
What is important to keep in mind during the ammonium test?
The gas tested on the litmus paper in ammonia (NH3)
What is the positive result for copper (ll) and the chemical symbol?
Blue precipitate Cu(OH)2
What is the positive result for iron (ll) and the chemical symbol?
Green precipitate Fe(OH)2
What is the positive result for iron (lll) and the chemical symbol?
Orange precipitate Fe(OH)3
How do you carry out the test for chloride, bromide and iodide? (2)
- Add silver nitrate
- Then acidify with dilute nitric acid
What is the positive result for chloride?
White precipitate
What is the positive result for bromide?
Cream precipitate
What is the positive result for iodide?
Yellow precipitate
How do you carry out the test for sulphate? (2)
- Add barium chloride
- Then acidify with dilute HCl
What is the positive result for sulphate?
White percipitate
How do you carry out the test for carbonate?
- Add some acid
What is the positive result for carbonate?
Cloudly/milky
What is the chemical symbol for ammonium?
NH4^+
What is the chemical symbol for copper (ll)?
Cu^2+
What is the chemical symbol for iron (ll)?
Fe^2+
What is the chemical symbol for iron (lll)?
Fe^3+
What is the chemical symbol for chloride?
Cl^-
What is the chemical symbol for bromide?
Br^-
What is the chemical symbol for Iodide?
I^-
What is the chemical symbol for sulphate?
SO4^2-
What is the chemical symbol for carbonate?
CO3^2-