Explanation:
option A skeleton system is correct option
hope this helps you !
Chemical reaction is given as :

Here, 2 moles of water gives 2 moles of hydrogen and one mole of oxygen.
Mass of hydrogen = 28.0 g (given)
Mass of oxygen = 224.0 g (given)
Number of moles = 
Thus, number of moles of hydrogen = 
= 14 moles of hydrogen
Number of moles of oxygen= 
= 7 moles of oxygen
Now, to find the amount of water:

= 252 g of water.
Thus, amount of water is 252 g (involved in the process).
Copper oxide
As the gas in the air i'm assuming it's Oxygen.
Answer:
SiCl4 + H2O = SiO2 + HCl
Reactant. product
Si = 1 atom Si = 1 atom
Cl = 4 atom Cl = 1 atom
H = 2 atom H = 1 atom
O = 1 atom O = 2 atom
SiCl4. + 2H2o = SiO2 + 4hcl
Reactant. product
Si = 1 atom Si = 1 atom
Cl = 4 atom Cl = 4 atom
H = 4 atom H = 4 atom
O = 2 atom O = 2 atom
Balanced chemical equation.