Name some properties of transition metals
- Form coloured compounds
- High density
- High melting/boiling points
- less reactive than group 1 metals
- Used as catalysts
Name some properties of halogens (Group 7)
- React with metals to form halides
- Melting point decreases
- 7 outer shell electrons
Halogen + Metal = ?
Sodium + Chlorine = ?
What is displacement?
When a more reactive halogen replaces a less reactive halide
Displacement example: Fluorine + Sodium chloride =
Sodium fluoride + chlorine
What ions make water hard?
Calcium (Ca2+) AND Magnesium (Mg2+)
How is scum formed?
When hard water reacts with soap
Can soft water lather easily with soap?
What is scum?
When calciumor magnesium ions from hard water and stearate ions from soap form an insoluble precipate
What are the two types of hard water?
Temporary and permenant
How can temporary hard water be softened?
By heating it as it will decompose
Describe how an ion exchange column can soften per
The exchange column has a resin that contains sodium or hydrogen ions.
Once the hard water passes through the resin, the sodium/hydrogen ions replace the calcium/magnesium ions in the hard water.
Why is chlorine added to hard water?
To kill harmful bacteria/disinfect
Why is a catalyst used?
To lower the activation energy
What is simple calorimetry?
A method used to measure neergy given out in a combustion reaction
What did Dmitri Mendeleev do to improve the period
- He left gaps for any undiscovered elements
- Recalculated atomic masses
- Lined up elements with similar properties
Name some properties of alkali earth metals (Group
- Very reactive (Stored under oil)
- One outer shell electron
- Low density
Explain why the reactivity increases as you go dow
The outer most shell is further away from the positively charged nucleus.
This means the outer most electron has a weaker force and therefore can easily be lost.
Explain why the reactivity decreases as you go dow
The number of shells increases
This means there is a weaker attraction between the outer most electron and the nucleus
It becomes less easy to gain an electron
Why is titration used?
To find out how much acid is needed to neutralise an alkali
What indicator would we use for a strong acid + a
What indicator would we use for a weak acid + a st
Why do we carry out flame tests?
To test for metal ions
What colour flame is potassium?
What are the first three members of a homologous s
What do alcohols react with to produce hydrogen?
What can ethanol be oxidised to?
What's the functional group of the carboxylic acid
Carboxylic acids dissolve in water to produce...?
How can we tell if an acid is weak?
If it doesn't ionise completely when dissolved in water
What is the functional group for esters?
Ethanol + Ethanoic acid =