Answer:
Gases we Breathe Out
It is the same air that we inhale. ... The amount of inhaled air contains 21% of oxygen and 0.04% of carbon dioxide, while the air we breathe out contains 16.4% of oxygen and 4.4% of carbon dioxide.
Physical changes:
- Try to scratch with other metals to find the hardness
- Try to deform to find the maleability
- Heat it and measure the temperature to find the melting point
Chemical changes
- Put it in water to see if it reacts and if the reaction is violent (metals from group I and II react with water and Li, Na and K does it violently)
- Put it in acids of different strength, to observe if they react. Metals of second group react rapidly with acids. Other metals react only slowly with acids and others are almost inert.
From the equation;
4 Al + 3 O2 = 2 Al2O3
The mole ratio of Oxygen is to Aluminium hydroxide is 3:2.
Therefore; moles of Al2O3 is
(0.5/3 )× 2 = 0.333 moles
Therefore; The moles of aluminium oxide will be 0.333 moles