From the equation: 
4mol Li react with 1 mol O2 
Molar mass Li = 7g/mol 
mol in 84g Li = 84/7 = 12 mol Li 
From the equation - 12 mol Li will react with 3 mol O2 
At STP 1 mol O2 has volume = 22.4L 
<span>
At STP 3 mol O2 has volume = 3*22.4 = 67.2L O2 gas will react. </span>
        
                    
             
        
        
        
Naproxen is known to be a weak acid. In order to calculate
its ka and pka, use the equation of getting the ph of weak acid which is ph=
-1/2 log [(Ka)(Mwa)]. The Ka value is 3.18x10^-5. The pKa can be obtained
through pKa = - log Ka. The pKa is 4.5. 
 
        
                    
             
        
        
        
Answer:
characteristics i believe 
 
        
                    
             
        
        
        
The percent yield of the reaction : 89.14%
<h3>Further explanation</h3>
Reaction of Ammonia and Oxygen in a lab :
<em>4 NH₃ (g) + 5 O₂ (g) ⇒ 4 NO(g)+ 6 H₂O(g)</em>
mass NH₃ = 80 g
mol NH₃ (MW=17 g/mol):

mass O₂ = 120 g
mol O₂(MW=32 g/mol) :

Mol ratio of reactants(to find limiting reatants) :

mol of H₂O based on O₂ as limiting reactants :
mol H₂O :

mass H₂O :
4.5 x 18 g/mol = 81 g
The percent yield :

 
        
             
        
        
        
Answer:
D. In both, vibrations occur in a parallel direction to the direction of the wave.
Explanation:
It is not true that in both mechanical and electromagnetic waves, vibrations occur in  parallel direction to the direction of the wave. 
As with all waves, they are disturbances that transfers energy without moving the materials of the medium. 
- Electromagnetic waves have only one way of propagation which is a vibration in both parallel and longitudinal direction.
- Mechanical waves can be propagated either in a parallel direction or longitudinal direction and not both.