According to the balanced chemical equation:
4 HPO₃ + 12 C → 2 H₂ + 12 CO + P₄
4 moles of HPO₃       ---gives---> 12 moles of CO
2.73 moles of HPO₃  ---gives---> ? moles of CO
so number of moles of CO = 

 = 8.19 moles of CO
Number of molecules of CO = number of moles * Avogadro's number
                                       = 8.19 * (6.022 * 10²³) = 4.93 * 10²⁴ molecules
 
        
             
        
        
        
Try out answer C magnesium oxides melting point is almost 5 times higher than magnesium
        
             
        
        
        
Answer:
0.098 moles H₂S
Explanation:
The reaction that takes place is 
- 2H₂(g) + S₂(g) ⇄ 2H₂S(g)  keq = 7.5
 
We can express the equilibrium constant as:
- keq = [H₂S]² / [S₂] [H₂]² = 7.5
 
With the volume we can <u>calculate the equilibrium concentration of H₂</u>:
- [H₂] = 0.072 mol / 2.0 L = 0.036 M
 
<em>The stoichiometric ratio</em> tells us that <u>the concentration of S₂ is half of the concentration of H₂</u>:
- [S₂] = [H₂] / 2 = 0.036 M / 2 = 0.018 M
 
Now we <u>can calculate [H₂S]</u>:
-  7.5 = [H₂S]² / (0.018*0.036²)
 
So 0.013 M is the concentration of H₂S <em>at equilibrium</em>.
- This would amount to (0.013 M * 2.0 L) 0.026 moles of H₂S
 
- The moles of H₂ at equilibrium are equal to the moles of H₂S that reacted.
 
Initial moles of H₂S - Moles of H₂S that reacted into H₂ = Moles of H₂S at equilibrium
Initial moles of H₂S - 0.072 mol = 0.026 mol
Initial moles of H₂S = 0.098 moles H₂S
 
        
             
        
        
        
By lowering temperature from liquid to solid, atoms lose some of their energy, when atoms slow down, they move close together and make the matter denser.