Do now! Can you read through the notes we made last lesson?

Do now!Can you read

through the notes we made last

lesson?

Last lesson

• Reactions of sulphur dioxide in water and with alkalis

• Laboratory production of carbon dioxide

• Reactions of carbon dioxide in water and with alkalis

Sulphur dioxide SO2

Produced by burning sulphur (or burning fossil fuels)

S(l) + O2(g) SO2(g)

In water

Dissolves to form sulphurous acid

SO2(g) + H2O(l) H2SO3(aq)

With an alkali

Forms a sulphite

SO2 + 2NaOH Na2SO3 + H2O

Carbon dioxide

Preparing carbon dioxide

Acid + carbonate salt + water + carbon dioxide

2HCl + CaCO3 CaCl2 + H2O + CO2

In water

Dissolves to form carbonic acid

CO2(g) + H2O (l) H2CO 3(aq)

pH 5.5

In alkali

H2CO 3(aq) + 2NaOH(aq) Na2CO3(aq) + 2H2O(l)

acid + base salt + water

Today’s lesson

• Uses of carbon dioxide

• Oxides of nitrogen

Uses of carbon dioxide

Fizzy drinks. The higher the pressure, the more soluble the gas becomes.

So what happens when the pressure

is released?

Uses of carbon dioxide

Dry ice (actually it’s condensed water vapour that you can see.)

Uses of carbon dioxide

Fire extinguishersHow does it

work?

Oxides of nitrogen

Nitrogen is generally an unreactive gas, and needs fairly extreme conditions to get it to react with oxygen

Nitric oxide, NO

Lightning brings about the direct union of nitrogen and oxygen in the air to produce small amounts of nitric oxide, as does the high temperatures produced in car engines.

Nitric oxide, NO

It is a toxic air pollutant, often linked with asthma and allergic responses

Nitrous oxide, N2O

Formed when ammonium nitrate, NH4NO3, is heated. A colourless gas with a pleasing odour and sweet taste, is used as an anesthetic for minor operations, especially in dentistry.

Nitrous oxide, N2O

It is called laughing gas because of its intoxicating effect. It is alsowidely used as a propellant in aerosol cans of whipped cream!

Nitrogen dioxide, NO2

In the presence of excess oxygen, nitric oxide, NO, will be converted to nitrogen dioxide,NO2. Nitrogen Dioxide is a reddish brown, toxic gas at room temperature. NO2 condenses to a brown liquid, but freezes to a colourless solid.

Nitrogen dioxide, NO2

Nitrogen Dioxide has been used as a catalyst in certain oxidation reactions; as a nitrating agent for organic compounds; as an oxidizing agent; as a rocket fuel; and as a flour bleaching agent

Stick them in

Can you stick the slides in your books?

Fractional distillation of air

Can you carefully read through the sheet. Then condense it to 4 sentences of no more than 12 words a sentence.