A) what is the rate-law expression for the reaction? do not add multiplication symbols to your answer or states of matter.
rate=

b)what is the value of the rate constant at 1200 k?
-1s-1

The answer is !

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.

Naoh + hbr -> nabr (salt) + h2o ca (oh)2 + 2hbr - - - > ca (br)2 + 2h2o