I think there might be just 4 or 5 chloropropene. 
        
             
        
        
        
Answer:
2.63*10^23
Explanation:
1 mol rhodium = 102.91
44.8g/1 mol * 1 mol/ 102.91mol * 6.022*10^23/1 mol =
2.63*10^23
 
        
             
        
        
        
Molar mass:
O2 = 31.99 g/mol
C8H18 = 144.22 g/mol
<span>2 C8H18(g) + 25 O2(g) = 16 CO2(g) + 18 H2O(g)
2 x 144.22 g --------------- 25 x 31.99 g
10.0 g ----------------------?? ( mass of O2)
10.0 x 25 x 31.99 / 2 x 144.22 =
7997.5 / 288.44 => 27.72 g of O2
hope this helps!
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The average speed is calculated using the following formula
Where

T = 298 K [room temperature] 
m = mass of each molecule of oxygen
mass of one mole of oxygen molecules = 32 g / mol
mass of one molecule of oxygen will be = 
mass of one molecule of oxygen will be = 
putting values
average speed = 
Average speed = 482.19 m / s
average speed = 1735.8 km / h
so approx = 1700 km/h