cân 0,6 KHS03 CHO VÀO 500ML NƯỚC CẤT, TA THU ĐƯỢC DUNG DỊCH a. tính pH và đệm năng của dung dịch A. Biết axit H2SO3 có các hằng số phân ly Ka1=1,7.10-2, Ka2=10-7

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.

1) according to the law of conservation of mass ,in all chemical reactions total mass is unchanged