The following balanced equation shows the formation of water. 2H2 + O2 2H2O How many moles of oxygen (O2) are required to completely react with 27.4 mol of H2

13.7 moles of O₂ are needed

Explanation:

In order to find the moles of reactants that may react to make the products we need to determine the reaction:

Reactants are hydrogen and oxygen

Product: Water

2 moles of hydrogen can react to 1 mol of oxygen and produce 2 moles of water.

Balanced reaction: 2H₂(g) + O₂(g) →  2H₂O(l)

If 2 moles of hydrogen need 1 mol of oxygen to react

Therefore, 27.4 moles of H₂ must need (27.4 .1) / 2 = 13.7 moles of O₂

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

i would say b

explanation:

but i think i would need more information than that