Answer:
Explanation:the best guess I will go with is H but I might be wrong
Movement from place to palce
A. Fe2O3 + 3CO= 2Fe+3CO2
Here element oxidised is CO or Carbon Monoxide, since oxygen is added.
B. 2HCl+2KMnO4+3H2C2O4=6CO2+2MnO2+2KCl+4H2O
Here Element reduced is 3H2C2O4, since Hydrogen is being added. Also KMnO4 is reduced, since Oxygen is removed.
Volume percent = Volume of solute
----------------------------------
Volume of the solution
2 Volume of the solute
------- = ------------------------------
100 250
Volume of the solute = 2 x 250
------------
100
= 5 mL.
Hope this helps!