INORGANIC CHEMISRTY

How do group one metals react in water?

• they react vigorously

• They produce a metal hydroxide solution

• Produces hydrogen - fizzing

What is the word equation for sodium (group 1) and water

Sodium + water → sodium hydroxide + hydrogen

What happens to group 1 metals when left in air?

• they react with oxygen, forming oxides

• they tarnish, leaving a dull metal oxide layer.

What is the word equation for alkali metals in water?

Metal + water → metal hydroxide + hydrogen

What is the reactivity trend in group 1?

As you go down, the elements become more reactive.

Where can the group 1 metals trend in reactivity be seen?

• rate of reaction with water to react completely with the water and disappear

• Rate of reaction with oxygen to react and form its oxide

Why does group one reactivity happen?

• all group one metals have one electron in their outer shell

• As you go down group one, the atoms get bigger, the outer shell distance from nucleus increase

• The attraction between the outermost electron an the nucleus becomes less, the outer electron is more easily lost and therefore more reactive

What is chlorine at room temperature?

• fairly reactive

• Poisonous

• Green gas

What is bromine at room temperature?

• poisonous

• Red-brown liquid which gives off orange vapour

What is iodine at room temperature?

• dark grey crystalline solid

• Gives off purple vapour when heated

What is the trend of boiling point and colour of halogens?

• as the atomic number increases, the elements get darker and have higher boiling point.

what is the reactivity trend of halogens?

• the reactivity decreases going down group 7

why does the reactivity trend happen in group 7 metals?

• halogens have seven electrons in their outer shell.

• the more shells there are, the harder it is to attract the extra electron to fill the outer shell when its further away from the nucleus

• the atoms with less shells are therefore more reactive as they can easily attract the extra electron.

what happens when two halogens react with eachother?

the more reactive halogen will displace the less reactive reactive one. a colour change will occur

what happens during displacement reactions?

• displacement reactions are redox reactions.

• an electron will be passed from the less reactive halogen to the more reactive halogen.

what is the proportions of gases in the atmosphere?

78% nitrogen

21% oxygen

1% argon

0.04% carbon dioxide

what does iron do to air?

it reacts with oxygen in the air, to form rust, therefore removing oxygen from the air.

how to investigate the proportion of oxygen in the air using iron?

1. soak iron wool in acetic acid, then push the wool into a measuring cylinder

2. invert the measuring cylinder into a beaker of water and record the starting position of the water (starting volume of air)

3. over time the level of water in the cylinder will rise

4. this is because the iron reacts with the oxygen to make iron oxide

5. leave the measuring cylinder for a week or until the water level stops changing

6. record the finishing position of the water

how to investigate the proportion of oxygen in the air using phosphorus?

1. place the phosphorus in a tube and attach glass syringes at either end

2. make sure one is filled with air and the other is empty

3. measure the starting amount of air

4. heat the phosphorus and use the syringes to pass the air over it

5. the phosphorus will react with oxygen to make phosphorus oxide

6. as it reacts, the volume of air will decrease.

7. measure the final volume of air.

what is the formula for calculating the percentage of oxygen in the atmosphere?

(start volume - final volume) / start volume x 100

what happens when magnesium combusts?

• bright white flame

• forms magnesium oxide (white powder, slightly alkaline when dissolved in water)

what happens when hydrogen combusts?

• pale blue flame

• forms water (as water vapour)

what happens when sulfur combusts?

• pale blue flame

• produces sulfur dioxide (acidic when dissolved in water)

what happens when you heat a metal carbonate?

• thermal decomposition

• carbon dioxide and metal oxide formed

what happens when copper carbonate is thermally decomposed?

CuCO3 → CuO + CO2

you can test the gas thats given off for CO2

what are the greenhouse gases?

CO2, CH4, water vapour

what do greenhouse gases do?

they naturally act like an insulating layer, absorbing heat that would be radiated out into space, re-radiating it back to earth.

how does human activity effect the amount of CO2?

• deforestation means less CO2 is removed from the atmosphere via photosynthesis

• burning fossil fuels means carbon that was “locked up” in these fuels is released as CO2.

• increasing amounts of CO2 affects climate change, increasing temperature.

balanced symbol equation for combustion of magnesium

2Mg + O2 → 2MgO

balanced symbol equation for combustion of hydrogen

2H2+ O2 → 2H2O

balanced symbol equation for combustion of sulfur

S + O2 → SO2

Equation for acid + metal

Acid + metal → salt + hydrogen

Mneumonic for reactivity series

Please stop lying cause my African zebra is cunty slay girl

Reactivity series

Potassium Sodium Lithium Calcium Magnesium Aluminium Zinc Iron Copper Silver Gold

Describe the test for measuring rate of reaction between HCl/HSO4 and metals

1. Setup 3 boiling tubes and fill them with equal volumes of dilute HCl or HSO4

2. Then place equal sizes of magnesium, zinc and iron into diff test tube

3. The speed of the reaction is indicated by the rate at which the bubbles of hydrogen occur

4. You can test for hydrogen by using squeaky pop test

How doe magnesium react with cold dilute acids

• vigorously

• Produces lots of bubbles

How do zinc and iron react with dilute acids

• slowly

• More strong if heated

Equation for metal + water

Metal + water → metal hydroxide + hydrogen

What metals react with water

• very reactive metals

• Potassium, sodium, lithium, calcium

What metals react with steam

• less reactive metals that wont react with cold water

• Magnesium, zinc, iron

How do potassium, sodium, lithium and calcium react with water?

• Metal + water → metal hydroxide + hydrogen

• vigorously

• Produces bubbles of hydrogen gas, which can be tested

How do magnesium, zinc, iron react with steam?

• metal + steam → metal oxide + hydrogen

• Soak mineral wool with water, heat it in test tube

• The steam given off will react with metal in a test tube

• The gas given off will then burn when lit with a burning splint

What happens when two metal react

• the more reactive metal will displace the less reactive one

• Displacement reaction - redox reactions

What happens when a metal oxide and metal reacts

• the more reactive metal will displace the less reactive metal from its oxide as it will bond more strongly to the oxygen

• The metal is oxidised and the displaced metal ion is reduced

What happens when a reactive metal is placed into a solution of a less reactive metal salt

• the reactive metal will displace the less reactive metal

• If a reaction has occurred, the temperature will change

• A more reactive metal will give a greater temperature change than a less reactive metal

In what conditions does iron rust?

• when the iron is in contact with both oxygen and water

What is the word equation for rusting of iron?

Iron + oxygen + water → hydrated iron(III) oxide

How to prevent rusting

• barrier methods: painting/casing it with plastic or oiling/greasing it

• Galvanisation: coating it with zinc, as it is more reactive than iron, so it will be oxidised instead

• Sacrificial protection: placing a more reactive metal with the iron - the water and oxygen react with the metal instead of the iron

What is the oxidising agent?

The substance that is reduced

What is the reducing agent?

The substance that is oxidised