For the following hypothetical reaction: 3a+12b--> 4c, how many moles of b will you need to convert 5 moles of a into as many moles of c as possible? (enter just the number; not the number and units)

 The  number  of   B that will be needed  to convert  5   moles  of A  into as many  moles of C as possible  is  20  moles

   Explanation

3A  + 12 B →  4 C

The  moles  of B  is calculated  using the mole ratio  of A  to B    from  equation above

that is the  moles  ratio  of  A:B  = 3 : 12

Therefore the  moles of  B = 5 x12/3 = 20 moles