Question

hydrogen (a moles) and iodine (b moles) react to give 2x moles of HI at equilibrium. The total number of moles at equilibrium is

Answer 1

you just have to balance the equation,

total number of moles = a+b

the solution is given in the image given below.

i hope it helps.

Answer 2

hope it helps you !
best of luck for ahead !