Making and Testing Gases

Question 1

describe the laboratory preparation of oxygen from hydrogen peroxide, using manganese(IV) oxide as a catalyst

Answer 1

• hydrogen peroxide is put in a conical flask with manganese(IV) oxide as a catalyst. Plus there could be some water to dilute the hydrogen peroxide.
• Hydrogen peroxide > water + oxygen 2H2O2 > 2H2O + O2 You can then collect oxygen by downwards displacement method

Question 2

describe the laboratory preparation of carbon dioxide from calcium carbonate and dilute hydrochloric acid

Answer 2

• calcium carbonate + hydrochloric acid → calcium chloride + water + carbon dioxide
• CaCO3 + 2HCl → CaCl2 + H2O + CO2
• made by reaction of dilute hydrochloric acid and calcium carbonate (marble chips)

Question 3

describe the formation of carbon dioxide from the thermal decomposition of metal carbonates such as copper(II) carbonate

Answer 3

• When metal carbonates are heated they become carbon dioxide and a metal.
• For example:
• copper carbonate > copper oxide + carbon dioxide
• CuCO3 > CuO + CO2

Question 4

what are the properties of Carbon dioxide?

Answer 4

• colourless, odourless gas
• denser than air
• slightly soluble in water
• used in fizzy drinks and fire extinguishers

Question 5

explain the use of carbon dioxide in carbonating drinks and in fire extinguishers, in terms of its solubility and density

Answer 5

• Carbon dioxide is dissolved into drinks at a high pressure, this makes CO2 bubbles in fizzy drinks.
• Some fire extinguishers have CO2 in, because it is denser than air it will fall over the fire creating a barrier between the air and fire: the fire can’t burn with out the oxygen in the air.

Question 6

whats reaction do we get when carbon dioxide reacts with sulphur dioxide with water?

Answer 6

• acid rain is caused when water and oxygen react with
• sulphur dioxide to produce sulphuric acud
• oxydes of nitrogen (NO_x) to produce nitric acid