Question

When heated, KClO3 decomposes into KCl and O2. If this reaction produced 88.4 g of KCl, how much O2 was produced (in grams)? 2KClO_3--->2KCl+3O_2. A) 2(KClO_3)=245.096 B) 2KCl=149.102g C) 3O_2=95.995

Answer 1

Mass of KCl=          88.4g 
Molar mass of KCl=39+35.5 
                                =74.5 
 The Moles of KCl= 88.4/74.5
                            =1.186
If for  the 2 moles of KCl there are 3 moles of oxygen
so

1 mole of KCl will  give=3/2=1.5 moles of oxygen 

1.186 moles of KCl will give =1.5*1.186=1.779 oxygen
32 the molar mass of oxygen
so its mass will be
1.779 *32=56.928
enjoy