ideal gas law. but you are talking about moles of gas not miles
Well, if you look at group 1 of the periodic table, you will notice a thrend. All elements in group 1 have 1 valence / outer electron. Then you look at period 2, 3, 4 and so on, you will see that the group number corresponds the number of valence/ outershell electrons. Hence, the group determines the electron(s) on the outershell.
Answer: 25.8 g of 
will be produced from the decomposition of 73.4 g of 
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
2 moles of produce = 3 moles of
Thus 0.242 moles of will produce= 
of
Mass of = 
Thus 25.8 g of will be produced from the decomposition of 73.4 g of
Hey there!
Exothermic reactions release heat, causing its temperature to fall. If the reaction is lessening the temperature of the object while releasing all the heat, then you know that the reaction is indeed exothermic. Hope this helps!
