D) Contain Chemical bonds.
        
                    
             
        
        
        
Answer:
30.62 L
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 55 L
Initial pressure (P₁) = 3.2 atm
Initial temperature (T₁) = 520 K
Final temperature (T₂) = 760 K
Final pressure (P₂) = 8.4 atm
Final volume (V₂) =?
The final volume of the gas can be obtained as follow:
P₁V₁ / T₁ = P₂V₂ / T₂
3.2 × 55 / 520 = 8.4 × V₂ / 760
176 / 520 = 8.4 × V₂ / 760
Cross multiply 
520 × 8.4 × V₂ = 176 × 760
4368 × V₂ = 133760
Divide both side by 4368
V₂ = 133760 / 4368
V₂ = 30.62 L
Therefore, the new volume of the gas is 30.62 L
 
        
             
        
        
        
Explanation:
(a) potassium oxide with water

According to reaction,1 mole of potassium  oxide reacts with 1 mole of water to give 1 mole of potassium hydroxide.
(b) diphosphorus trioxide with water

According to reaction,1 mole of diphosphorus trioxide reacts with 2 moles of water  to give 2 moles of phosphorus acid.
 (c) chromium(III) oxide with dilute hydrochloric acid,

According to reaction,1 mole of chromium(III) oxide reacts with 6 moles of hydrochloric acid to give 2 moles of chromium(III) chloride and 3 moles of water.
(d) selenium dioxide with aqueous potassium hydroxide

According to reaction,1 mole of selenium dioxide reacts with 2 moles of potassium hydroxide to give 1 mole of potassium selenite and 1 mole of water.
 
        
             
        
        
        
Answer: The mass percent of hydrogen in ascorbic acid is 4.5 %
Explanation:
In  , there are 6 carbon atoms, 8 hydrogen atoms and 6 oxygen atoms.
, there are 6 carbon atoms, 8 hydrogen atoms and 6 oxygen atoms.
To calculate the mass percent of element in a given compound, we use the formula:

Mass of hydrogen = 
Molar Mass of ascorbic acid =
Putting values in above equation, we get:

Hence, the mass percent of of hydrogen in ascorbic acid is 4.5 %.