Alkali metals
What is the word equation for an alkali metal reacting with water? Write the equation for sodium and water with state symbols.
What colour would the solution turn if i added universal indicator?
Alkali metal + water → Alkali metal hydroxide + hydrogen
2Na(s) + 2H2O (l) → 2NaOH (aq) + H2 (g)
Whats the difference between a halogen and a halide?
Halogens are diatomic molecules whereas halides are compounds formed between an element and a halogen (ions)
Name 4 differences between metals and transition metals
Transition metals are used as catalysts, form coloured compounds, have variable oxidation states, hard and strong, high density, high melting and boiling points, low reactivity
What is a displacement reaction?
A more reactive element displaces a less reactive element
Write the symbol equation for potassium and water reacting
include state symbols
2K(s) + 2H2O(l) → 2KOH(aq) + H2 (g)
What are some uses of the halogens?
Chlorine - water treatment
Iodine - disinfectant
Explain why argon is unreactive and give one use of argon?
Has a full outer shell (found as monoatomic)
Welding/lamps
Describe how you could show MgO is a basic oxide and not an amphoteric oxide
React it with an acid and an alkali, if it was amphoteric it would react with both of them. However it only reacts with an acid therefore is a basic oxide.
What happens to reactivity as you go down the group and why?
Increases
There is only one outer electron in group one therefore as you go down the group there is a greater distance between this electron and the nucleus meaning the electrostatic attraction between them decreases as well as an increase in shielding meaning it is easier for this electron to be lost
Which halogen(s) will displace bromine from a solution of potassium bromide?
Fluorine and chlorine
Name two processes where we see transition metals used as catalysts from last year - what do they both produce?
Haber - ammonia
Contact - sulfur trioxide
As you move across a period what change happens in:
i) Structure
ii) Atomic size
iii) Oxides
i) Giant metallic to giant covalent (Si) to simple molecular
ii) atomic size decreases
iii) Basic to acidic
Name 4 properties of alkali metals as you go down the group
Density increases
Gets softer
MP and BP decreases
Reactivity increases - flames produced
State the symbol, colour and state of the the halogens at room temperature
What are the trends then as you go down the group?
F2 - Gas - Pale Yellow
Cl2 - Gas - Pale green
Br2 - Liquid - Red-brown
I2 - Solid - Grey with a purple vapour
As you go down the group you change from gas to solid and the colour gets darker
Which transition metals are magnetic
Iron/Cobalt/nickel
The oxidation states of vanadium in its oxides are V(5+), V(4+), V(3+), V(2+)
The vanadium (III) ion can behave as either an oxidising or reducing agent, which one is acting as an oxidising agent in the following equation and how can you tell:
2V3+ + Zn → 2V2+ + Zn2+
V3+
It has oxidised Zn and itself been reduced/ Zn has increased in oxidation number and V3+ has a decrease in oxidation number
Describe 3 observations each for what happens when these alkali metals are added to water:
i) Lithium
ii) Sodium
iii) Potassium
i) Keeps it shape but gets smaller/ floats and moves on the surface/ effervesces slowly
ii) Melts into a ball/ floats and moves on the surface/ effervesces strongly
iii) Melts into a ball and lights with a lilac flame/ floats and moves on the surface/ Effervesces violently
What is the equation for bromine reacting with potassium chloride?
What colour is the colour change?
Sike
Manganese is a transition element with several oxides:
Manganese (II) oxide : basic
Manganese (III) oxide : amphoteric
Manganese (IV) oxide : acidic
1) Write a word equation for manganese (II) oxide and HCl
2) Which, if any, will react with sodium hydroxide?
1) Manganese (II) oxide + hydrochloric acid → Manganese (II) chloride + water
2) Manganese (III) and (IV)
Choose an element from the list below that best suits these descriptions
Rb/Fe/Si/I/P/Sr
1) An element that reacts with cold water
2) A solid at room temperature and exists as a diatomic molecule
3) It can form two oxides - XO, X2O3
4) Forms a hydride - XH3
5) Has a macromolecular structure similar to carbon
1) Rb/Sr
2) I
3) Fe
4) P
5) Si