O2 20.95 H20 0 to 4 Ar 0.93 CO2 0.036 Which two of these gases/ vapours are produced when a fossil fuel is burned? The amount of water vapour present in the air is the most variable. Suggest a reason for this. [2008 OL][2009 OL][2012 OL] Name any three gases normally found in clean air. [2012] Describe an experiment, using a labelled diagram to show the presence of carbon dioxide in air. [2012] Give a test to show that the droplets formed on the outside of a glass containing a cold drink are water. [2006] The composition of air can be investigated in different ways. Two experiments are shown in the diagram. In Experiment A the air was pushed repeatedly over the heated copper powder and only 79 cm3 of gas remained at the end of the experiment. Why is it necessary to let the apparatus cool down before measuring the volume of the remaining gas? Why did the volume of gas decrease and then remain steady? is the remaining gas mainly composed of? Experiment B is less accurate than Experiment A. Give a reason why this is so. [2006 OL] What happens when a piece of wood) is placed in a gas jar of oxygen? “glowing splint” (very hot Give one property of oxygen that this demonstrates. [2012] What substance is formed when carbon is burned in oxygen? Give the effect of this substance on moist litmus paper. [2008][2010 OL][2008 OL] The diagram shows magnesium being burned in oxygen to form magnesium oxide (MgO). What colour was the flame? Pieces of moist blue and red litmus paper were mixed with the product of the combustion. What result was seen? conclusion can be made from the result of the litmus test? [2011] The apparatus shown in the diagram was used to strongly heat 2.4 g of magnesium in a crucible. The lid of the crucible was lifted a little during the heating. A white powder, with a mass of 4.0 g, was produced.
O2 20.95 H20 0 to 4 Ar 0.93 CO2 0.036 Which two of these gases/ vapours are produced when a fossil fuel is burned? The amount of water vapour present in the air is the most variable. Suggest a reason for this. [2008 OL][2009 OL][2012 OL] Name any three gases normally found in clean air. [2012] Describe an experiment, using a labelled diagram to show the presence of carbon dioxide in air. [2012] Give a test to show that the droplets formed on the outside of a glass containing a cold drink are water. [2006] The composition of air can be investigated in different ways. Two experiments are shown in the diagram. In Experiment A the air was pushed repeatedly over the heated copper powder and only 79 cm3 of gas remained at the end of the experiment. Why is it necessary to let the apparatus cool down before measuring the volume of the remaining gas? Why did the volume of gas decrease and then remain steady? is the remaining gas mainly composed of? Experiment B is less accurate than Experiment A. Give a reason why this is so. [2006 OL] What happens when a “glowing splint” (very hot piece of wood) is placed in a gas jar of oxygen? Give one property of oxygen that this demonstrates. [2012] What substance is formed when carbon is burned in oxygen? Give the effect of this substance on moist litmus paper. [2008][2010 OL][2008 OL] The diagram shows magnesium being burned in oxygen to form magnesium oxide (MgO). What colour was the flame? Pieces of moist blue and red litmus paper were mixed with the product of the combustion. What result was seen? conclusion can be made from the result of the litmus test? [2011] The apparatus shown in the diagram was used to strongly heat 2.4 g of magnesium in a crucible. The lid of the crucible was lifted a little during the heating. A white powder, with a mass of 4.0 g, was produced.
5.%20The%20Air%20and%20Oxygen.docx