Answer: 8.7 grams
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
 of particles.  
To calculate the moles, we use the equation:


As oxygen is in excess, Aluminium is the limiting reagent and limits the formation of products.
According to stoichiometry:
4 moles of aluminium give = 2 moles of 
Thus 0.17 moles of aluminium give=
Mass of 
Thus the mass of 
  is 8.7 grams
 
        
             
        
        
        
Answer:
U= 238g/mol
U2O5= 556g/mol
Explanation:
Since U= 238
 O=16
U3O5= 2(238)+3(16)=556g/mol
 
        
             
        
        
        
Answer:
we will except an increase in the polarity of the system and this will cause the Non-polar spot to be near the solvent front, while the polar spot will run at an approximate speed of 0.5 Rf 
Explanation:
when we run a TLC plate in a 50/50 mixture of hexanes and ethyl acetate we will except an increase in the polarity of the system and this will cause the Non-polar spot to be near the solvent front, while the polar spot will run at an approximate speed of 0.5 Rf 
The speed of the polar spot depends largely on the level of polarity, an increase in the polarity will see both spots of Neat hexane run when we run a TLC  plate in a 50/50 mixture of hexanes and ethyl acetate
 
        
             
        
        
        
Explanation:
The answer to questions are 
A) 4
B) 3
C) 5
D) 3
E) 3