The equation below is balanced. H2(g) + Cl2(g) → 2 HCl(g) What is the total number of moles of HCl(g) produced when 3 moles of H2(g) is completely
consumed?
2 moles
6 moles
3 moles
5 moles

The reaction will shift to the right

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.