Urgent needed when 100 liters of butane, c4h10, are reacted at sp (standard pressure) and 25°c. how many liters of oxygen are required under the same conditions? 2 c₄h₁₀(g) + 13 o₂(g) ⇄ 8 co₂(g) + 10h₂o(l)

the balanced equation for the reaction is as follows
2C₄H₁₀ + 13O₂ ---> 8 CO₂ + 10H₂O
 stoichiometry of C₄H₁₀ to O₂ is 2:13
stoichiometry applies to the molar ratio of reactants and products. Avagadros law states that volume of gas is directly proportional to number of moles of gas when pressure and temperature are constant.
 Therefore volume ratio of reactants is equal to molar ratio, volume ratio of C₄H₁₀ to O₂ is 2:13
 2 L of C₄H₁₀ reacts with 13 L of O₂ 
then 100 L of C₄H₁₀ reacts with 13/2 x 100 = 650 L
 therefore 650 L of O₂ are required